Every role but DPS is spread thin enough, and I'm pretty sure most DPS wouldn't jump to the "Support" role.

Besides Healers do enough supporting as is. This game doesn't need overly supportive spells. Like, look at WHM and how Protect(Proshell) works in this game.

Also,you are asking for SE to put a lot of time and effort into changing how their game works in balance with the current roles.