If the admins have a laissez faire approach, then they can go fuck themselves. The difference between a nuke and defederation (well, there are many, but the main one here) is that defederation can be undone. If the admins don’t like their instance being isolated, they can fix the problem by getting rid of the comm. If they are that committed to allowing the comm, then it is correct to keep them defederated.
The one caveat I will give is that it would be incumbent on the other instances to follow through on overturning the blacklist – and making sure their peer instances do – if shitjustworks actually does comply eventually.