Yes, because the world doesn't actually work that way.
The liability is on the seller, and as such the price of insurance should either be built into the cost of the product if they're requiring it or part of their business plan when it comes to expected losses. When you're buying a product you're creating a contract between yourself and the vendor, the vendor is responsible for getting the product to you, they then subcontract with a shipper to do that part of the job.
Offsetting insurance cost to you is a dick move, but it does help them recover losses that aren't yours nor theirs technically, but a lack of shipping insurance doesn't absolve them of their part of of your business contract- you entered into an agreement with them, they're required to follow it. Personally, I won't do business with people who require extra insurance like that- build it in or gtfo. Yes, that means I'll pay more to someone who doesn't require it even if its more than price+shipping+insurance of the other guy.
