I really don't know what to say about pvp players. In those old times where no net was available, people played pvp on LAN and phone lines (Duke nukem 3d).
It was normally a group of friends, harassing each other to madness, trying the worse and having great fun. Everyone knew what they were doing, deathmatches were deathmatches, conquer the flag was teamwork, and the few games that offered cooperative play (everyone against the machine), people would really try to cooperate, despite always having that jerk on the team that was trying to mine all the fun.
But now, things seem more serious. I keep repeating, it's only a game, have fun. But when the stakes of loosing are higher than a simple respawn, I guess it's natural to hate the grievers.
But considering a minimal number of social-disabled chumps, I tend to think of PVP'ers as people who just want to have fun doing things that they can't in real life.