Melee had a lot of characters that could win, hell even bottom teirs got in there and owned from time to time. Thing is, Melee had less characters and more characters that were actually capable of winning a tournanent. Brawl has more characters to choose from and less characters that win and that's really bad. MK is the most used, most successfull out of every character because he:
A. Has no bad match up's.
B. No counterpicks against him.
C. No vital weaknesses found or ways to beating him.
D. Pretty much had auto L-Cancel built into him. (No areial lag)
E. Outprioritizes freakin everyone.
All this and more against him is all the more reason to ban. He's running the tourney scene and he's the user of most people who get 1st place at anything important too.
For those of you that want to try to be cool and be like "Oh, nope. No problem at all with that scrub lulz!!!", you need to check yourself. I don't know about you guys but if this crap keeps up I'm only playing Brawl+ (Brawl 2.0 as some of you might know, the hacked/alternative Brawl regulations) where things are a hell of a lot more balanced. It's so balanced MK is actually being debated to be moved down to high teir.