Well then don't buy anything from me on eBay, because if you want the insurance, you get to clicky the box to say so, and pay for it.
Yes, the seller would submit the claim, but that doesn't mean it's his responsibility to pay for the insurance out of pocket. Or, if you want the cost to be transparent (but you'll be paying it anyway), the seller can easily enough add $1.35 to the "and handling" costs.
I sell a lot of items on eBay. Nothing staggeringly valuable, but I do offer insurance. Less than 1% of the people opt to have the packages shipped insured.