Story, music and glamour. The story and music dies down of course after experiencing it multiple times, which leaves glamour as the only reason for me to continue after a 3 month interval waiting for new content. I'd say community but with the system currently the way it is I'm not sure I'd even count that as a reason to play.
Plenty of endgame content is locked behind 8 player groups and I can que up for 3 hours for some savage or extreme mode I can't try because players already done it or there's other content to be ran. Doing this also severs links to certain players. Statics are nice, really they are, but making it in such a way is singling out players. If SE would allow players to use these modes in df at the start I would mention these challenges but they're not all that accessible as of now.
The battle system is highly "meh". I don't consider it much of one other than being flashy. Except for the caster classes and range ones of course, they seem more fit for these things (target system and all). You really don't get much oonf in doing attacks other than the players who love seeing big numbers. I prefer impact over math. Not saying it doesn't matter as it's all math in just about everygame, but at least they're better at giving the player a feel of strength other than having to visually show it with numbers.
Its a theme park. Saying that kinda bores me but it is what it is. You seen the rides, you made the points, heard the jingles and enjoyed the sights. You can tell people to craft everything in game or level everything to max, but that won't count as player content that gives a reason to continue playing. Now I played Dark Souls 3. I played the game and don't feel like playing it anymore because I'm bored of it now. How can i get bored. I did just about everything and anything else would be repeating the same thing over again. Then a buddy tells me to upgrade all the weapons and armor, there's still much to do dude. Pretty much that. Except with that game you get pvp which makes it more worth playing if your into that, plus that always changes. 14 doesn't have much of that and is completely nullified with GC Alliances, lack of innovative modes and 1v1v1 battles. If you played pvp you know what I mean.
For some, these things are not worth it for a subscription based mmo. Kind of why I took my 3 month break from the game and came back for the story. I love my friends, but I think I have more respect for myself to know when enough is enough.