What a weird statement. I'm not even quite sure where to start.

Alternatives, for what purpose? What is this great utility that cryptocurrencies provide that you can't think of an alternative to?

So far there are only two - avoiding government regulation, what most people call "crime"; and speculation on a security with no fundamentals whatsoever.

Both of these are bad for society in general.

Now, if you come up with some application, the chances are I'm going to say this as an objection: "But you could do exactly the same thing for 0.1% of the cost that would work 1000x faster using boring old late 70s technology like strong encryption and Merkle trees. What do you need a consensus blockchain for?"