People complain about tanks, because they aren't skilled enough to play tank role themselves. I saw some tanks that should throw their PCs against a wall by being so bad (like running into a group of mobs and dont flash at all... or use fast blade -> riot blade combo only). I believe thats why i rerolled from BLM to PLD. Because i couldnt hold bad tanks anymore.
Ill continue tanking, because of my beloved insta queues (and my coil party which needs me badly :P), and i dont even care if they BM against me, or kick me... i have insta queues, and they will be stuck in a dungeon without a tank, or leave and be on queue for 10 minutes (or more).