They can illegalize it, just like they can try to make the sun or moon illegal.
Are they going to make decentralized anonymous money illegal. So what? It’s beyond their reach. Currently not illegal tho.
Yeah, I get that. Still, as someone else said, it’s like tulip mania. And at least, when you sell your home to buy a tulip bulb, you can always plant it and have a nice flower. :-P