Ok posting this in edits due to forum problem!
It would be unreasonable in a business sense to rate people on an individual basis. It would require infinitely more man power, more expenses, more people employed to do it. it would also take a lot longer to set up a policy, it would require interviews, history checks, you'd still need to compensate for liars and that's before you even get to accidents. Then of course prices would need to be bumped up to compensate for uninsured loss recovery because let be honest, if insuring your car required interviews and history checks, how could you not expect the ratio of uninsured drivers to increase exponentially?
Once you've factored in all these things, you'd probably end up paying more anyway.
Unfortunately lumping people together is the most efficient way, not just for the insurer, but for you, to do business. It just wouldn't be possible to add in more factors to a premium than there already is.