AUTO INSURANCE AND CREDIT REPORTS, What does one have to do with the other?

Does any one but me think its bull that one can be refused auto insurance or pay a higher premium because their credit score may be lower than some other guys. Why on earth are we letting car insurance companies get buy with this? Even auto insurance companies having access to our creit history makes no sence and is a further invasion of our privacy. This practice should be outlawed.
Again what does credit score and auto insurance have to do with each other?