Personally, I don't enjoy Moba's, or RTS games (some RTS games are okay). Mostly due to the fact that I've been devoted to working on myself. Team fortress 2 is different for me, I work on my own skills, but also my team skills. Through the years I have thought about quitting, only reason to quit at the current moment is due to real life issues; But quitting is not that easy. Not because of the game, but because of the community. Hell, even if I did "quit" I'll probably be in pubs/pugs & mumble with friends.
tldr; Quitting is not easy when you find a community that has people who stand out from the crowd.