There was a related discussion here on YC News.
The gist of it was that these hosting providers exchange credit for cash-equivalents. For example, you can sign up with a credit card, and then immediately start using the compute that you have purchased to mine crypto.
Now, if you pay your bill, this ought not to matter. Who cares what you use your rented computer power for? (As long at is not hideously illegal child porn hosting or what have you.)
The problem was that the smaller providers were being mercilessly abused by criminals signing up with stolen credit card numbers. They would extract sufficient crypto coins before the provider shut them down for this to be worth doing over and over.
The providers could have simply requested up-front payment for compute until a "track record" was established, and this would have solved the problem.
Instead, they all opted to maximise the "sign ups per month" metric to get those sweet, sweet KPIs met, and then killed the crypto-mining accounts mercilessly with AI detection.
... which also killed several legitimate customer's businesses outright. Typically with no recourse.
Oops.