It's already happening, I know that there are some shops you can shop with your crypto currency, even pundis have lunched their cryptos POS, so it's happening a lot just that it has not attracted mass adaption.
It is happened and many stores are accepting Bitcoin and some other coin for selling their projects but a majority of this community do not know about it at all as these shops do not advertise much. The have to advertise especially on this forum to aware all of them.