Button mashing is an infuriatingly effective tactic used by novices. I had a friend (past tense; there were other things annoying about him too) who thought he was awesome because he would button mash with Taki on Soul Calibur 2. And at my weekly social, half of everyone will button mash me to death. It's one hell of a way to reward a player who'd put some effort into learning how to play the way the developers instructed you.
As a semi-advanced player of SC2 I could personally counter a button basher by taking some distance, and then retaliate with long range attacks, guard impacts and large openings from those moves that take half the round to recover from. My friend who was "that guy" would quite invincibly tear players apart with Mitsurugi and look quite cool doing so. I place a "that guy" in higher regard than a masher because the former uses some skill to beat me.
However, I'm guessing that nobody who dispises button mashing actually does so themselves. Try to look at fighting games from their point of view. You don't know anything at all about how to play this fighting game, but you pick up the controls anyway. "FIGHT" shouts the announcer. What do you do? You have to do something. You start pressing the buttons of course. If you didn't get something out of your efforts, you'd be a bit peeved, especially so if you had stuck a coin into an arcade machine. In the case of an arcade machine, there has to be some reward to even just mashing the buttons.
As for console fighters, there isn't that much help for beginners stuck with mashing. I own SC2, which is why I'm good at it, but not 3 or 4. So when I find that most of the moves that I know are gone (this was thinking that Ivy wouldn't have changed drastically, pfft), I now don't know many moves to pull off. And perhaps I am punished for my objecting to mashing, since I can barely survive by the basic triangles of horizontal-vertical-dodge and attack-block-throw.
Looking at it that way, the blame has to lie with the developer and not the masher. The machinics stand there and reward button mashing, and perhaps purposely too. If you don't own a particular fighting game, the only way you're going to progress your skills beyond mashing is to read a guide somewhere, forgetting what you've read by the time you get back to playing again. You don't get a bunch of friends around to learn how to play a game and hone some skills, you just want to play the thing, and then everyone gets stuck in button mashing as the game doesn't really want to tell you how you could play better.
I suppose the reason why console FPS's are so popular is because everyone knows by just looking at the box that the control scheme has been copy-pasted from Halo.
Idea of the year: Show each player a move from the movelist of their chosen character during the loading screen.
