Solo-Queue RBG's?

So I've been wanting to do some RBG's lately to get a vicious saddle but the RBG premade groups are more viceral than pugging Mythic NH.It got me thinking... Why do they not implement a Solo-queue RBG system that is based on MMR? They should make a viewable ladder, with divisions and leagues(like in League of Legends) and end-of-season rewards. Even extend this type of system to arenas!Why is this not a thing? I would participate so much more in PVP if it didn't have such a high barrier of entry for ranked premades and basically no rewards or progression for unranked.