The truth is that the anticipation for crypto to go mainstream increases as time goes on. In fact there are skeptis who would have nothing to do with crypto unless it goes mainstream. Is 2018 that year when blockchain crypto goes mainstream?
I don't see it happening this year. We are already nearing end of the year and only a few nations have fully accepted Bitcoin or crypto as a whole. Mainstream is still quite far from happening for crypto. But I have no doubt that Bitcoin/crypto will become mainstream some time in the future.