Because there's literally nothing else for me to spend my free time doing other than watching TV (no thanks), or going to play another MMO (definitely not happening).

Seriously though, FFXIV is probably the best MMO on the market right now. The raids are really fun, and the people I play with make the game even more fun. Sure, I spend most of my day sitting at my FC house while I'm watching YouTube, but knowing that I'm not going to find a better experience elsewhere is what keeps me here.

Having said that, I'm not the kind of person to go out and level every job, crafter, and gatherer to 50. If I were, I'd still have more than enough to do. There are things in the game for me to do, I just choose not to do them.