Nothing about game-play (in the sense of what my opponent does in-match or which character(s) they play) is really going to sway me toward any sort of emotional tipping point---I play(ed) Alpha 2, Super Turbo and Tekken 5 DR at high level, and I think those games all pretty much wiped out my ability to become upset over even the most egregiously busted mechanics/tactics. i.e.: All games are broken and/or have bullshit.
1.) I rage-quit MK9 when I get declined 20 times in a row whilst searching for opponents via Player Match. I get so annoyed that every time one of them declines me, I send them a message to let them know just what I think of their cowardice. (I have a 1790-248 WL record or something like that, and people seem to think that means something. Idiots.) It's more annoying when it's somebody with a W-L ratio on par with mine, obviously just looking to fight scrubs. In the poker world, we call that Bum Hunting; but the difference with MK9 is that it's not profitable in any monetary sense, so the only incentive for doing so is to appeal to one's own pathetic ego.
2.) Input shortcuts and negative edge causing unwanted specials to come out. Input shortcuts are dumb, end of story. I should not be able to pull off a d,b+2 with Sonya simply by holding d/b and hitting 2. I have adapted my SFA2 ways to simply holding down, but it's still retarded that that happens. As for NE, it simply has no purpose in MK9. NE is useful for garnering more "input equity" during reversal situations, but since MK9 is so lax about execution, it really serves no purpose. NE is useful for Guilty Gear and BlazBlue characters, but I can think of no MK9 character who wouldn't be better-served by the abolishing of this mechanic.
3.) The fact that you cannot quit at the character select screen without taking a loss---after having moved the cursor around and determining just how ridiculously unplayable the match will be. That is retarded.
4.) People not having the fucking compatibility packs. Is it out of spite? Ignorance? Apathy?
5.) Always 4 bars/balls for every person in every chatroom, because the internet is just THAT awesome now.
6.) People who quit after one match and, when you question them about it, proceed to tell you that it is because: "ur gonna ruin my ratio d3wd!". Online is serious business, apparently.
7.) People who, no matter what, call you a "spammer". This doesn't really annoy me, though, because I like to mess with their heads by asking them questions which lead them to conclude that the only logical stance to have on the matter is that they lost because they simply do not know how to deal with a basic, fundamental situation in the game. There will always be scrubs.
8.) Random standing attacks coming out while obviously holding crouch. Mmmm, yes!
9.) Throw breaking system - I don't mind that you cannot break throws on block, and my willingness to adapt to that system is predicated on the fact that I think it serves as a great instigator for deliberately engaging the opponent. However, 1+2 should be a universal break, period. Aren't all throws as fast as, if not faster than Mad Axes?