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?
2018 is just another year whereas cryptocurrency such as bitcoin is becoming popular day by day. In my opinion, I think 2018 is not the year yet for a reason that when we say "mainstream" it is the common thing about something and crypto is not being use by most of the population of the world. However, in some places, the usage of crypto like bitcoin is somehow considered as mainstream. I hope that day will come.