USPS Insurance

What a joke! Occasionally I sell junk on ebay which requires shipping my item(s). Each time I'm at the post office they ask me if I would like to purchase shipping insurance. I always politely decline, but last time I was there I got to thinking...why should I have to pay insurance? I am paying for a service, which is for them to take my parcel from its present location and deliver it to the destination of my choice. If it doesn't make it there in one piece, why should that be my burden? While we're on that subject, if it doesn't make it there AT ALL, that is also somehow my fault for failing to purchase a tracking number. Let me get this straight, I (the customer) am paying you (the service provider) to move my goods from point A to point B, but if it breaks on the way, or doesn't arrive at all for that matter, it's 100% my responsibility because I didn't purchase the *additional services*. Ludicrous.