Your approach is certainly commendable, and I agree that such an approach would be a good way of promoting bitcoin as currency. One of the problems people most often encounter when dealing with bitcoin is its great volatility, which is a big obstacle when it comes to paying sometimes. It is difficult to explain to people that price of bitcoin can go up / down in the amount of several thousand dollars, and while it is not a problem when price is going up, certainly it is in the case where there is a sharp downs.

What we need is stability of the price, and a way to prevent price manipulation - and this is almost impossible now. It is an indisputable fact that most users use bitcoin just as store of value / investment, and that a smaller percentage uses bitcoin for payments. This percentage is further reduced in low-priced periods, it is not same to pay 500$ at 3000$ bitcoin price or at 6000$.