People are still gonna do FATEs because in FATEs you don't have to be accountable for gear or your ability to play the game. Its just a zerg where no one really has a role and you just do whatever. In a dungeon, you have a defined role and its much easier to see if you are actually being competent or not. I feel that there will be many people who will not want that responsibility and scrutiny and would rather just still do FATEs where they can be lone wolfs doing whatever they want.