What made you quit XI or switch over to XIV? Do you still play both or have you gone back to XI after playing XIV? What's new?
Me personally, I quit XI after I got XIV. I like XIV a lot and I think it has great potential and Yoshi-P seems like he's doing a great job.
XI was fun and the 6 years I played on it are memorable, but the game wasn't what it used to be. I feel people are too comfortable doing things a set way. If a PLD didn't have a RDM, he wouldn't join. If there was no BRD, people wouldn't bother. If you're tank was a NIN they would say "no, thanks". I enjoyed doing crazy shit. Going into a party and I (THF) was duo tanking with another THF. I had gotten so much EXP from that and we never stopped pulling until nothing was there to pull. The waiting for party invites that never came, no matter what job you were. Even as a PLD, alls I got were: Party? Level sync 37? No. I want to use the full extent of my character at level 66. Level sync should not be used to gain easy levels, just to even out exp.
Though I have some friends who still play say a lot of new stuff has come out and it sounds cool. I may try it again on a new server.
Although it is fun to actually be part of a new MMO and watching it "grow".
So those are my reasons, what are yours?