Now let's imagine the victim tells the hacker they are not willing to negotiate and hope that law enforcement will catch the hackers like they did in the Bitfinex case. The hacker could destroy some coins every X days to make it clear to the victim that this is not a good idea.

This is just a wild scenario. But had I been the Bitfinex hacker I would have done crazy things such as sending blacklisted coins in small amounts to many random addresses, those of exchanges, developers, non-profits, Satoshi Nakamoto etc.. Just to create chaos as it would have caused those people a lot of trouble and would have forced some kind of resolution.