Along with the fact that if you take away Tank and Heal DPS, you'll have really long DF queues and have a hard time getting anyone to want to play those jobs anymore.

Well, I'm leveling all my DPS because if I have to DPS as a Healer, better DPS as a real DPS-class without the added responsability of keeping everyone alive. In my POV, changes would make queues faster, not slower.