I don't understand why the insurer cares whether or not the lender's collateral is getting what they want. Shouldn't that just be a matter between the insured and the lender?
Theoretically, yes. The insurer has a contract with the insured, the insured has a contract with the lender, the insurer and the lender have no contractual relationship.
Traditionally, lenders lent on the basis of collateral; the home or the car. They quickly figured out that, if the collateral was damaged, the insured/borrower could collect the insurance payment but not repair the collateral, and the lender would be SOL.
So lenders created two solutions to this problem: (1) they inserted themselves into the insurer/insured contract by making insurance loss payee status a condition of the loan contract, and (2) changed the terms of the loan contract to allow them to collect from the borrower beyond the collateral stated, if the collateral proves insufficient.
Fun story: about 10 years back, someone I worked with was writing the insurance on a POS mini golf course. The thing burned down (of course it did, it was a POS firetrap), so we wrote out the check to the owner and called it a day. EXCEPT that the underwriter who handled the account had been lazy and instead of putting on a loss payee form saying "POS Bank LLC", they put the form on saying "As per schedule on file with the company". When the Claims department called up saying "Where's this schedule?" the guy couldn't find it, so he told Claims there wasn't any loss payee on file.
A few months later, POS Bank realizes they haven't been getting paid, go to investigate and find their collateral a bombed out ruin. They contact us because the owner had given them a certificate saying "look, you're a loss payee", and they're able to show that the insured HAD submitted a schedule listing them.
So we paid that claim twice. Good times.
The lazy guy is still with the company. Last I heard, he'd gotten promoted. Insurance is a great career path, kids.