they and their ilk behind the Credit Score here in the US are a law unto themselves... opaque measurements based on often inaccurate data with no real recourse for the person being scored or a sensible way to provide input to the system.
recently the providers have, um, colluded to come up with an "insurance score" which uses a subset of your credit history to decide if you're a good/bad insurance risk ... not your driving record, your age, where you live ... but the balance on your credit card.
Because I have the nasty habit of using the credit card companies money - I keep a high revolving balance so for 30 days money is earning me interest (and my credit card even gives me an extra 1% cashback!) but I always ensure I have cash on hand to cover the amount owed - I am deemed to be a credit risk ... as a result my insurance quote just more than doubled with an insurer who I've been with - accident free - as long as we've lived in the US. Luckily in this case a phone call sorted the problem out, but as automated schemes like this gain more credibility people will be forced to change their common sense behaviour to follow some hidden rules designed to make life more rewarding for those offering credit and insurance.
I agree with Pypes ... a basic "at cost" scheme provided by the state with optional private "top up" options would be the way to go and force a fairer playing field