Everything in the IT is like building bridges.
There was a time that people did start building bridges, a lot of them collapsed, but they kept improving and nowadays you rarely hear about bridges collapsing. Unfortunately one did last week and it was major news, it even reached mainstream media here in Europe.
It will be the same for cryptos, block chain and so on. But I do believe that there will be at least an equal number of blockchains without cryptocurrency than with.
Will dedicate a post to that later this week or early next week.