You could also draw different conclusions (that would be just as speculative and possibly not true), such as: Introverts are more sceptical of or averse to "popular" things, more rigid in their way of thinking ("hate") etc.

Personally, I don't think I'm not reward-sensitive or that I can't deal with too much stimuli, but I'm not very competitive and I like to do things at my own pace, which is why most multiplayer games don't have much appeal to me.

GOG is focused on single player games that you can play offline, so that's not all that surprising. Judging from my experience, I'd also say that fans of multiplayer games tend to concentrate on just a couple of specific games and would therefor be more likely to hang out at those games' forums rather than a general gaming forum.

Why should it? I meet friends and do RL stuff like acting or playing non-computer games or band practice whenever we all have time. But being extrovert doesn't mean that I have to be compulsively among other people all the time. Sometimes I'm home on my own and then I play computer games. Sure, I'll never be a hardcore gamer who can compete in tournaments, because I don't practice gaming 10 hours a day. But that's not my goal with playing games. It's just having fun.

Introvert, hate achievements.

My husband is an introvert, and pursues them to a damning degree (ruining his enjoyment to get that elusive 100%).

I am an Alb. Emotions are pointless. Videogames are pointless. All Elex to the Hybrid.

Good answer.
I guess the problem lies with my being lazy and borderline agoraphobic.

Introvert, I usually access achievements in a game before I eventually care about them, if they are made in an interesting fashion and add to the experience I will mind. If they ask to grind or to do stupid stunts or unpractical things I will ignore them.