It's a bit of a tragedy of the commons, not sure who will be the third party to impose a cost onto cryptocurrencies that consume excess energy. So far bitcoin has maintained it's lead as the largest cryptocurrency essentially entirely due to network effect. For most major complaints against bitcoin there is an example of a crypto currency that doesn't have those 'failings'.

E.g.

Deflationary good: siacoin

Long tx times: Ethereum

Proof of work consumes needless energy: Peercoin

ASICs shift the power balance: Primecoin

Not anonymous enough: Monero

A singular append only blockchain is not enough: Byteball (it's simply a DAG of transactions)

The problem is that there is no centralized player that is currently exerting a cost, above mining costs, on the individuals to move them to a crypto currency that doesn't have whatever negative property is being rallyed around at the moment.

That is just waiting for some type of disruption. Not that I can predict what that disruption would be but things this inefficient can not be an optimal end state for this type of technology.