if i play against a braindead person, i will win no matter what.
if i see what my opponent does and i can't defend it, i shouldn't have been matched against it in the first place. of course, maphacks won't get a bronze player to grandmasters, but he WILL win more games than he would without.
also, there ARE maphacks in sc2. some users get banned, some don't. if you watch a replay and see somebody blind cannon rushing your starting position on a 4 player map wihtout any scouting... how do you think he is able to do that and still win more than half of his games?
Alright, I agree maphack gives them advantage, but high level players don't give a damn to it