Yeah, I gotta be honest, I can't stand a lot of the stages on Brawl. (Although some that are banned aren't too bad.) If you're playing IN TOURNAMENT, (note the key words) would you be happy if you lost to some random guy that you KNOW you could beat? Why would that happen? Well it's all because of the stage. I can't tell you how many times I've lost because Pictochat is...well not even fun, in my opinion. It is far too random. Plus, you need to realize that stages that are banned isn't because of glitching. I can guarantee you that MORE people would be complaining about ALL the stages being on instead of a good amount being banned. Also...there wouldn't be a tournament scene...because people wouldn't go. Then again....I don't think any TO out there would go for the stages. Most people don't like all the stages.
Plus...it's really not nice to just say, "Ban glitch abuse". I'm sure if you found a neat little trick the book didn't tell you about and you used it. You'd be mad if someone called it a glitch, and told you not to use it. (Be honest with yourself) Also....it's not nice to assume that we're banning stages because you can't employ glitches. Would you rather have a game like MVC2, where everything is ruled pretty much by Sentinel, Magneto, and Storm? (I love MVC2, btw....but that is a bit frustrating.My first time playing it in an arcade and I get hit with infinites both matches. Guess what team it was?)
The rest is pretty much what those two, said.