Sometimes ins. companies want to limit or cease writing certain lines of coverage in a state because of various factors. These factors could be their overall experience with that type of policy and their loss ratio, could be a result of political actions, societal, etc.
If they notify the state ins. dep't. of their intent, the state tells them that if they want to do business in the state, they have to offer ALL lines of coverages or they can't do business.
The ins. company then simply raises the rates so high that people will not renew with them on those lines of coverage. Problem solved.