Comparing Spamhaus to credit scoring agencies
While both can (disingenuously) claim "we don't block your email/credit" they are both responsible for sourcing the information that does. With credit rating companies, we all have a right to access the information they hold about us and have it corrected if it's wrong. With Spamhous we have no rights, no means of getting incorrect information put right and we aren't even judged on our own behaviour.
In human rights terms collective punishments are illegal. You cannot punish a group of people for the wrongdoings of one, whom you suspect of being in that group. Yet this is precisely what happens with Spamhous. What's worse is that you, as an individual, have no rights to have information that Spamhous publish about the IP address you are using updated. While you could argue that with dynamic IP allocation it's not practical, that doesn't excuse the behaviour, which is simply a poor implementation which addresses the wrong problem.