My appetite for PvP dropped off precipitously after college. I just don't have the time to dedicate to getting good at any game, and every online multiplayer game I've ever played is toxic if you aren't at least decent. I have no interest in a sixteen year old cursing me out because I don't have the map memorized.

Single player generally also brings in much more flexibility, especially when it comes to things like mods. With my limited free time, if I'm enjoying a game except for thing x, I prefer the ability to remove or diminish that thing x. Also, you have the ability to pause to change laundry loads or whatever.