Perhaps I wasn't as clear as I should be. Sure registering with a state's insurance commission requires that the insurance company comply with regulatory requirements. But why would I want to buy a policy from a company that does not currently do business in Missouri? And why would they want to sell a policy to me?
This is America, we’re supposed to have interstate commerce. If you choose not to do business with out of state firms that’s up to you. But if someone want’s to buy a policy from a company in another state, why shouldn’t they? Generally increased competition is a good thing. You have some states where there are only one or two companies to choose from.