Same can be said about a hundred other things in the world. All the way from knives to nuclear.

Bad actors could and will train their own models eventually. So what's the point of crippling frontier? It will only delay preparations for dynamic of new world prolonging the fake sense of relative safety and temporarily lowering motivation to find actual robust mitigations.

Letting bad actors dictate the pace of technological development is certainly one option, but not a good one.

There's nothing stopping anyone from doing it, even without AI. People have proved entirely capable of doing a lot more hacking than happened here.