Because the price of these shoes is ridiculous and they don't last as long as regular shoes. I'm probably also not running anywhere near fast or efficient enough to properly utilise the benefits of them properly.
I could see them getting banned in pro racing at some point. Didn't nike publish results that their shoes could get something like 3% faster race times for a marathon. For most people that wouldn't matter but at an elite level it could become pay to win as the shoes get better. The same thing happened in swimming with low drag speedsuits.
Yeah but at what point is that no longer human talent? Are there regulations on footwear for these records? If not what's to stop someone from using the spring legs that can make you run a hell of a lot faster?