I've already proposed a similar system in the past, I even developed it to the point of being to make card payments in Bitcoin. I almost had it ready for demo at Coinfest 2016 and the general concensus (on here at least at the time) was that Bitcoin is fine as it is and there's little need for a faster confirmation time. I'm still developing for Bitcoin but my focus has moved onto a new payment system based on Ethereum tokens (and not another coin with an ICO to raise funds)