The issue with FATEs is that it gives really high XP while
1) Not really needing to gear up
2) Not really needing to know the core mechanics of your class
3) Basing rewards on "monster tagging" and damage
4) Giving scarcely any compensation whether you're just trying to tackle the event with two players instead of twenty

IMO it's either the XP or all the rest that needs to be fixed to balance things out. I'd hate to see any more content being converted into XP piñatas instead, though at least battleleves need a serious buff.