You haven't even tried applying wavedash in Brawl have you?
Samus'z Zair isn't crazy with wavedashing, it's still got enough end animation to not be able to wavedash into something else.
Pit's arrows, wtf...only implementation I can see is a well timed arrow loop and a wavedash into something, not broken, just technical.
ZSS, well I haven't played as her yet but I'm sure she isn't that broken.
MetaKnight isn't ultra broken with a wavedash. =/
You seriously just missed my point.
The fact is: YOU CAN ONLY AIRDODGE ONCE!!
Pit can arrow spam you all day long when you are off the stage and you can't airdodge or you will die. A competent Pit can prolly get 20ish free damage from this.
Samus can do the same, only worse because she can already zair someone off the stage multiple times into a blast zone. without multiple air dodges you can't escape it without falling to your doom.
Speaking of MK.... and ROB for that matter.... they can just follow you off the stage and keep hitting till you are screwed. then they can make it back because of their awesome recoveries. You will have a hell of a time avoiding them because you can't airdodge the attack and get behind them.
ZSS is one of the few of the cast that can escape some of these tactics due to the 12 frames of invulnerability in her flip jump. (and the threat of a very powerful spike
)
She also gains a lot of combos that are ruined by being able to airdodge before hitstun ends. Sure people can still airdodge them, but they become helpless and run the risk of being dsmash stunned and ending up worse off.
Seriously.... due to the general floatiness of brawl, the better projectile games, and the amazing recoveries of certain characters the limitation of a single airdodge is a very big deal!