???? Just re-upped insurance on my commercial property holdings this week and what you say above was about exactly opposite of what actually happened for me. Yes, higher insured values does translate into higher premiums, but higher insured values also allow the owner to collect more $$ if there is a loss.
Now then, the insurers did NOT determine insured values, they asked me as the owner what the value is and I told them. Yes, if I gave them some wacky number there may have been more scrutiny, but the process was not at all how you described it.