@Kestrel Competitiveness is not the only reason people might prefer a PvP game, no. But then, as long as people are not being toxic jerkasses, does it matter, from a game design point of view? It’s not the people who play nice with others that we need to worry about as admins.
Personally, I’m pretty competitive. I prefer a PvE environment, but I am unable to stop myself from looking at word counts and whatnot. And because I have a strong competitive streak, I stay the hell away from environments where I might not be able to keep it under control – for example, despite being an equestrian in real life, I have never started in a competition. Wouldn’t be fair to the horse or anyone else, having to listen to me bitch about not winning.