Yes there wouldn't such a big problem if FF14 was stable. Then it would be a rivalry shake hands on different approaches.
But right now FF14 is on a death bed and Rifts is not. No matter how you slice it FF14 is doing something wrong, Rifts is doing something right. That's the point.
It's less about styles then it is about what works so you need rifts to be in the picture, almost any single MMO can slap around FF14 as of right now.