The fact that in some (many?) places it's illegal to set insurance rates based on credit reports should tell us something: that at best they're an unreliable measure, and at worst they're (ab)used to discriminate.

No, it indicates that politicians are pandering to the voters who don't like it being used. If it wasn't useful insurance companies wouldn't do it.

Note that exceptions to the correlation has both false positives and false negatives.

e.g. On opposite side of people with bad credit who got hit by unavoidable circumstances, there are people like my partner who have limited credit score upside because they don’t use much credit. My partner has a mortgage with me, but other than that, she doesn’t have any debt and doesn’t use credit cards (other than the prepaid variety which pull directly from bank accounts and don’t contribute to credit scores.)

> The reality is that credit rating has a strong correlation with responsibility.

No, the reality is that responsibility is but one component of credit rating - another, moreso, being 'how attractive are you as a customer to credit providers'.

This is why your score might drop when you pay off an account, or close it. Defenders of the system and CRAs will say "well, there's less information to assess your creditworthiness now that that account is closed", as if, say, you had ten years of on time payments on that account, but they mean nothing.