Reason(s) I stay: My friends and FC.

Main Story - Done
Side Quests - Done
Crafting/Gathering - I have WVR and MIN at 60 but the rest are all below 50. Leveling them is boring
Glamour - Always need more Glamour, ALWAYS
Mount-/Minion-farming - Meh, don't really care :/
Raiding - No thank you. I tried to do a Static with my FC right before AS 5-8 came out, made me not want to be around them and a dreaded every Raid Day.
Housing - My FC has a mansion, so I don't need a house
Minigames - The GS minigames are lame, Triple Triad is a grind, LoV is non-existent
24-man Raids - Have it on Farm
Sightseeing - To much work for little reward
Beasttribes - Still need to finish the Amalj'aa, Sajagin, and Ixal but it's so boring and I don't care about their stories... :-B
Dungeons - Have it on Farm
Seasonal events - Done
Leveling multiple classes - Still have to level but it's so boring and I have all the Jobs I like playing as at 60.
Mentoring - Mentoring is a mess in this game. People are becoming mentors because they want a crown next to their name and they want the achievement rewards, not because they actually want to help people.
Making Gil - Yeah, no. :/
Relic Weapons - Slowly working on it but we all know the Relic Weapon is going to be replaced come a patch or two, which makes it feel like I'm grinding for nothing.