Here are my thoughts on some rather disrespectful Sm4sh behaviors...
Taunts Used At Inappropriate Times
By that, I don't mean taunting after a well-earned, stylish KO, especially if it ends the match. I'd taunt too, to be honest. I'm talking about taunting because of a Self Destruct or a freak accident. I mean...you aren't the above party if you did little to nothing about KOing someone.
Players Switching Into a Lackluster Little Mac/Powerful Character After Losing
I've been getting this more and more, and it really is annoying me. I want to fight the other character, not your Day 1 Little Mac that Dash Attacks, F-Tilts, and Smashes all day, nor do I want to play against your Day 1 Greninja that spams Side B and D-Air. I want fun fights, not ones where it is easily visible that the player uses someone that has been considered powerful in an attempt to win.
"One-Track Mind" Players
By this, I mean any player that does something over and over and over again. I understand the phrase "If it isn't broke, don't fix it;" however, if such tactics are missing a bunch and hitting me only a few times, and one is using it as a "pray it hits" method, it just makes the battle really unpleasant.
That's what is on the top of my mind. I'll likely find more of these habits later.