Some good points in the OP, and I'd personally add:
1. People pretending to be interested in or even be fans of something just to get a chance to hate. on it or it's fans. C'mon, it's not like you're fooling anyone...
2. Victims. Some people act like the whole world is out to get them. They are always being treated unfair and there are conspiracies against them everywhere.
3. People with a love for generalisation. One fan saying something = a whole fanbase saying something, and for some reason they always look for the worst ones to be the representatives. According to these people a fanbase is ruled by some kind of overmind, making them all share the same evil thoughts.
4. There are people who just hate whenever a certain game/console/company gets a lot of love. It's like they have some kind of disease giving them extreme internal bleedings whenever something positive is said about said game/console/company.
