I think one of the major problems with a Support Role is that they couldn't survive by themselves.
Just look at XI's Bard. Great in a party, weak by itself. It is literally one of the few if not the only job that can't solo things, even when subbing Ninja. White Mages can solo better then a Bard.
Personally, I think they could make a DPS or Healer that focuses more on support, our Bard and Healers are only touching the surface.