wrote
.... if one company boots you, you may
find it difficult or impossible to find insurance elsewhere.

Tell me about it! When I moved from the hi-rate LA area to VA my auto
insurer informed me that they couldn't renew my policy because they were not
licensed to sell insurance in VA. So I started calling local agents, only to
find that I'd have to pay 10X what I had been paying for full coverage and
that only provided minimum liability! Why? Because my current ensurer had
refused to reinsure me! I finally found reasonable rates at a national
company (Geico), but that's the exception. The rest were like sharks in a
feeding frenze - "Wow, a safe driver we can stick it to!"