I can understand how you feel about competitive play, but reading through your post , you sound like you're playing the blame game more than anything
I could have understood how your perspective on playing the game and getting better until you said that you didn't understand how to short hop, which is possibly one of the most simple things to do in smash bros., and was even illustrated on the smash bros dojo during Brawl's pre release:
http://www.smashbros.com/wii/en_us/howto/technique/technique10.html
Not only that, short hopping has been in almost every platformer to exist, including the games you hold to such extraordinary prestige, the Super Mario series. Being able to short hop in Super Mario 64, Super Mario Sunshine and even Super Mario Galaxy require you to input it the same way; you lightly tap the button. I'm not trying to question your integrity as a gamer, but surely anyone who calls themselves a hard core gamer can manage to press and release a button quickly enough to do a shorter jump, I have been able to do so since I was about 6 years old, but I was a gamer since the beginning of the 90's and played games from the 80's so games didn't perpetually hold the players hand, but I digress. What kind of games do you play exactly?
You are taking all of the wrong steps when it comes to learning. You said you don't want to have to deal with wavedashing, but you can't even properly execute a short hop (Which I find hard to believe personally), so you really shouldn't even be worrying about how to execute a wavedash in general. That's like trying to learn how to drive an 18-Wheeler truck before learning how to drive a car, it's completely backwards and detrimental to the learning process. The thing is, I bet you can short hop, you probably just can't do it in battle because your temperament mid play goes out the window when you're being hit, and players take advantage of that state of panic when a players tactics are perpetually exposed and don't know when to do. I played a Kirby player the other night who would literally just use all of his jumps and down B from the sky, like I wouldn't see it coming from a mile away. I blocked it every time and punished him for it. When he realized it wasn't working he lost composure and suddenly forgot how to play the game and even killed himself a few times. Not necessarily saying this is your issue, but playing fighting games against another player it is crucial that you control your tempo mid play and adapt to a situation, which is something that you aren't familiar with since you play Mario games, where you don't have to worry about adapting to something new since the stage won't change and if you make a mistake you always have an extra life to attempt to do the same thing.
Contrary to your belief, fighting games have evolved and have kept evolving, and they have been every since the introduction of Street FIghter. thanks to street fighter we now have a games like Guilty Gear that share the same input methods but plays on a completely different level. From the same creators of Street Fighter we have Marvel vs Capcom (The vs series) that borrow the same inputs but has a completely different way of playing. From there we have other games that borrow similar inputs but use them in a completely different engine. We have games like Mortal Kombat that borrow a lot from street fighter, but have established their own play style and lead to the creation of games such as Injustice: Gods among us. We also have other games in the fighting game genre like Dragon Ball Z: Budokai Tenkaichi, a unique 3D fighter that doesn't use the same inputs but still has deep underlying mechanics, similar games being Gundam Extreme Vs. and the upcoming J-Stars VS. There are even simpler input based 3D brawlers like Power Stone for people who still want to play a friendly fighting game that still has some deep mechanics (Throw teching, dodging, ukemi etc.). We also have games like Virtua Fighter and Tekken who have there own established methods of inputs and playing but still borrow some inputs methods from street fighter and the like. If fighting games were not evolving then why does such a large variety exist? Why constantly make these games if they aren't going any where when they clearly are?
Fighting games are very accessible, if not one of the most accessible forms of entertainment for game players. If I can buy the game, put it in my consol and play it in any way I see fit, it is accessible. Among them and first person shooters you see them in a lot of TV shows and cheesy sitcoms as you see players haphazardly mash buttons at each other, even though they interpret that as one of the players completely dominating the other player despite the fact that its an illusive fantasy. As a fighting game player I can't believe you did a combo into a super by frantically punishing a singe button, but it is interpreted that way because it's the societal norm. Many players who casually play games tend to play fighting games by mashing buttons rapidly against one another, and these players are completely fine with it. Games like Street Fighter are the common culprit to this and the players are fine with it.
Now say we introduce a more seasoned player who knows how to apply what he knows in the group of inexperienced players. You will get two kinds of responses: Either along the lines of "Wow man, you're good" or "Wow, you're such a cheater", the ladder being the player who lacks humility and believes that this way of playing at the entry level should have granted him victory despite the fact that there will always be a better player at his level or someone who was more willing to put in the necessary time to get better at the activity, I know this from experience from playing at my local arcade. Which draws me to the conclusion based on your responses; you want to be the player on the TV. You want to be the person who can pick up the game at anytime and be the better player by simply mashing the button and win (This is evident since you admitted to being unable to implement even the simplest of tactics into your gameplay). You feel like you should be able to do those combos and best a player by simply "playing the game" (Which as posters have previously stated is arbitrary, since playing in practice mode is playing the game). You believe that tech skill is your downfall, but it isn't, it is many things:
1. You believe that obtaining tech skill is some kind of self-fulfilling prophecy that will allow you to best a player when that's far from true. The players that succeed are not succeeding on the merit that they are consistently technical, but also because they have experience and play smarter.
2. Your temperament mid game play prevents you from doing the most simple things. Your analytical mind becomes absent once you lose control of the match and you don't attempt to mix up your approaches.
3. You don't have the proper mindset when playing. Mindgames, spacing, reading the opponents moves, assessing players options based on their positioning are far more important than knowing how to wavedash.
4. You are learning the technical game from the wrong perspective. Even if you know how to wavedash there are still a wide plethora of things you need to understand before you can compete. When and when you shouldn't use crouch canceling against an approaching player, what direction should you tech when being thrown, perfect shielding a projectile approach or a predicted move, how to DI a certain attack, preparing to ledge tech an attack when your recover misses the sweet spot of the ledge. All of these things are far more fundamental to learn, and will yield greater success in your game play than learning how to wavedash in general. Not saying you should abandon learning the wavedash, but there are more things you must know before you assume that one technique is the absolute end-to-all-means of learning.
Honestly, no one really needs to learn tech skill, but people still do it? Why? Because it gives players a competitive edge. There is always going to be a player or group of players who are going to try to learn something that another player doesn't know to give them an edge, big or small, it doesn't matter as long it can throw the opponent off guard. So at this point every other player is going to try to learn something and eventually all this information becomes common knowledge, and given the era we live in these things can be accessed at almost any time on the internet, so even the high level competitive play is accessible, unlike in the 90's when knowledge had to be passed from word to mouth, making it much more difficult to compete.
One thing I could say is that games sometimes are bad at teaching players how to play without making i arbitrary, but some game actually still do a great job at doing it. BlazBlue is actually pretty great at teching entry level players how to play competitively and introduces players to things like cancels, grab techs and 50/50 mix ups. There are also great examples like Smash Bros. 64 and Melee with break the targets, which thought you how to use a players list of moves to effectively use a characters moves and recovery to hit the targets in a method that was just a game, which in my opinion was extremely brilliant. However, there are limits to this kind of learning, as you had to understand how to play against something akin to the unpredictability of a cornered beast: the human player. This is something that takes a while to learn and brings about such things as adaption and predictability, things that playing through classic mode cant teach a player.
In the end you have to draw the line at when there are things a player should already to know and when you should expand upon them. No one is forcing you to learn anything, and believing that you shouldn't have to put your best foot forward despite the fact that every other player is willing to is not a healthy method of learning, and is the perpetual issue with gaming today. Sure its going to be hard, but anything in life worth obtaining will, and always be as such.