From @DanMountSports: Why is there a need to change gimmicks that work on NXT when talent gets to the main roster? If it ain't broke, don't fix it.
It's a different audience. That is WWE's answer anyway. When Triple H was on the Steve Austin podcast he said he knew NXT was for the hardcore wrestling fan aka the people like us that watch all the shows, read about the backstage stuff and appreciate the good wrestling. On the main roster they appeal to a bigger audience including kids, so there's a sense from Vince McMahon that they need to cater the shows towards them a bit more. It makes a bit of sense although when it's clear that NXT is superior to Raw and Smackdown then maybe they need to consider running things more like NXT. Over the top gimmicks don't really work in 2015 compared to 30 years ago. Fans are smarter. We just want to see good performers in the ring and on the microphone. It really doesn't have to be that complicated.