But this isn't proposed regulation to prevent an "economy oriented around energy being put into finding hashes".

It's literally regulation to stop "Proof of work". Which is a generic algorithm that can be applied to other circumstances.

It could have applications in CAPTCHA's, or anti-spam.

It could be a critical component of other decentralized technologies, not just blockchain crypto currencies.

Making this math illegal JUST to kill cyptocurrencies seems a tad much, right?