As the one who suggested combining agencies, I really meant that the FAA would turn into 50 varieties for each state like the DMV already it. Like with CDLs, I wish the DMVs would be federally consistent and the DMVs would only make collections for the state but all states following the same speed, ratings, height, towing, License plates, etc., regulations.
I lived in New Mexico and didn't like not having a front plate. The reason I heard being thrown around is because the people didn't want to pay more for plates and issuing one plate kept the cost down. My opinion is that operating a vehicle is a privilege NOT a right and the extra plate would be a small additional price for added safety. After all, owning a car, insuring it and maintaining it are already higher costs for having the privilege of vehicle ownership.
My vote is for two plates in all states for all vehicles, and why not trailers, or towables, etc. so you can identify them when disconnected and you can't see the rear. Make it easier for everyone, not try and save a few cents having to produce a second plate.