I'm not sure where your context for requirement is coming from. There are plenty of other advanced techniques used regularly that aren't bound to any kind of penalizing rule but are still necessary to be successful (chains, DACUS, character techs, wavedashing/landing, out of shields, di'ing, hitstun cancelling). Dribbling wasn't made with spectators or regulations in mind. Dribbling prevents players from clutching the ball into their chest and then cannonballing through the court.
That's what I meant by saying that there's more to dribbling than that comparison gives it credit. My context for it as a requirement is that you literally cannot function in Basketball without knowing how to dribble. You show me a player who's function is devoid of dribbling in Basketball, I will place my foot directly in my mouth, but I'm thinking that isn't a thing.
The l-cancel technique is just there to be used
if you wanna, but it's not really an option in pretty much 100% of cases at the competitive level. This creates a divide between casual and competitive players that doesn't need to exist.
L-Cancelling is interesting but maybe you've never played at a level to see first hand what a missed L-Cancel will do. If you're chaining someone into a Falcon Knee of Justice, whiff (lol), then miss the L-Cancel, then you are set up for potential punishment when the enemy comes out of hitstun, in practice making failure a penalizing experience after all. Maintaining control of your character is as important as maintaining control of the ball in basketball, and in non-Brawl games L-Cancelling is a part of that. There's literally no changing that if you want to be successful, so this is also in practice as much of a requirement as dribbling is in basketball.
I know exactly what L-Cancel is capable of doing and not doing to your game. I play Sonic often a lot lately in Project M, and I would find him nigh unplayable without being able to l-cancel the drop kick.
I also don't think it would change the depth of the game if it removed the need for me to process that input for every single dive kick.
Having L-Cancelling is not a bottom line for me. I could take it or leave it. I actually played for many years without having experienced what the difference L-Cancelling can have on the game (I don't think the auto-L's in Brawl+ count). L-Cancelling can be mechanically dull but it still has an impact on the game. However, know this: there are maybe 3 to 4x as many combined Melee/PM players than Brawl (and we're also talking about a player base that will kick your (or my) *** with or without L-Cancelling) and they all play those games instead of Brawl for a reason. It's not exclusively for L-Cancelling, but L-Cancelling is part of that reason. If players genuinely didn't want to play with L-Cancelling, then I don't think it would be in Project M and the game just wouldn't be as successful as it is.
I just have this vision of a Smash that is easy to play, but difficult to master, the difficult part being the spacing, mind games, and choices you make on the field. I'm not unfamiliar with difficult inputs but I'm also not a big fan of them, and I've played games with massively difficult inputs for the right combos that take infinite amounts of practice like Blazblue.
I just don't think it's necessary for a fun, Nintendo-based fighter. It's not even necessary for the combat to be deep. It just seems extraneous and people have grown a liking to it simply because it functionally makes things "harder", and these days people seem to be all about not wanting things to be easier for new players, which is in-directly
killing pro-gaming and pro-gaming spectator-ship.