No one can anticipate every possible risk. That's why rules change over time. They should give advance warning, let people out of long-term contracts, or refund

No one can anticipate every possible risk. That's why rules change over time. They should give advance warning, let people out of long-term contracts, or refund prorated monthly bills if they're changing the ToS mid-cycle, but there's nothing wrong with defending yourself against unforeseen abuses. The people mining crypto on shared resources know they're abusing the system; they're just trying to take advantage and spoil things for everyone around them.