OmegaFenix
The Legendary Troll Hunter
I don't hate people, I just hate having to work with them in multiplayer. I can handle competitive multiplayer, but co-operative multiplayer is something I abhor. I think it's got to do with the fact that anonymous people in co-op like to be assholes, like do stupid shit and get themselves killed, then blaming you, etc.
That said, people do make mistakes, and I do so myself frequently. I don't like that feeling that I made a mistake and I've let other people down through it. It also places a fair bit of pressure on you to perform due to the fact that others are depending on you, pressure which I don't really have in SP.
All round, I just prefer SP to co-operative multiplayer. I like to rely on myself, and hold myself accountable for mistakes.
While I feel the same for most team based MP, I found that in the ME3 MP Demo even without talking to people (me and Murph where in our own channel) the two other players we played with where just fine. They killed enemies and I killed enemies and died alot waiting for someone to revive me. But I totally see what your mean, worst thing about Multiplayer games... other people.