Alright, I'll try to give as concise an answer as possible to your question if you'll do me the same favor.
My definition of competition is pitting equally matched opponents against each other. Rating is required to set that up, gear is not. So I believe that, while acquiring uber gear via PvP may be fun, it can only serve to hinder a truly competitive rated bracket/environment.
I hope that answers why I personally dislike the idea of competing for rating locked gear.
My question is: If the measure of your gear's worth is determined by comparing it to your opponents gear, then how are upgrades not merely cosmetic if you only plan on playing against equally geared players, (as you would in a properly matched rated bracket)?