Human nature. Seems some are oblivious to the point of making themselves out to be a victim of it rather than just prone to it as much as the other guy.
For instance:
Player A shoots player B in the face and Player B goes down.
Player B is mad. He's mad at player A. He thinks he has every right to be since he knows Player A only HOs and has no skill and is symptomatic of a disease that is killing the game (derivative rationalization at it's worst). The actual situation is simple cause and effect. B got shot down - B is unhappy about it - B blames A for this unhappiness. Player B feels the need to either PM Player A and tell him all about it or broadcast on 200 to the world about it (perhaps even start a thread about it on the forum). Either way, Player A collects a bonus of seeing Player B get twisted and rant and rave. Here's where the other half of human nature kicks in. Player A realizes he's smiling as he reads it. His serotonin levels rise. Player B is now the cherry on top of the sundae. Every time player B has a hissy (in game or elsewhere) Player A is amused. Enough so that if he suspects his opponent is player B he will probably face-shoot him just for the sideshow.
At any given time in AH one player wins an engagement and another loses. It's never a fair fight. The winner never plays right.
It's not how the game was designed to be played (in spite of the fact that it's exactly how the game was designed to be played). There will always be a percentage of these players succumbing to their most base nature (attributing perception as just cause). Some seem to revel in it. And it's always someone else's fault. And it's always the end of the world.