This is an issue that has been a plague upon computer RPGs for a long time. Every so often an RPG comes along that chucks the "holy trinity" of STR/DEX/INT (even if the names are different) out the window and just gives the character "Power" and has "Power" affect their Class abilities. But the games that do this also tend to have a rigid class system, so your healer won't be a god of melee or ranged combat as well.
I would agree that having the 3 stats be basically "red power, green power, blue power" is rather dry and boring. Finding the right balance so that all three are of use to everyone, but favors one "type" is not an easy task of course.
