Every person is unique, I think that's what frustrates most people and why sometimes things do not make sense but it only takes a single post code letter or a model type on your car to throw things out. You cannot produce a costing model which takes absolutely everything into account, on the whole the models probably work fine in 80% of occasions and the rest you get strange things happening (including super good cheap deals as well as stupid expensive ones). Most of the time these insurers are just the brokers, they are not setting the prices, they are getting the cheapest from the suppliers they have available to them.
We all forget that these are companies that are trying to turn a profit, if you ran the business and you found that 50% of customers took the first price offered and 50% took a discounted rate when they bartered with you, would you just offer the discounted rate off the bat to everyone?
Just to say, I am not an insurance agent, I just wanted to give an alternative perspective and 'walk their shoes' version to consider before we move into 5 pages of just mob based insurance bashing