That's his choice and fair enough as a business decision, but if he required a signature there would probably be no need for this thread.
And if the carrier were made to pick up the cost of their mistakes, there would either be fewer errors, or the carrier would be more expensive relative to others.
WRONG, I got hit for $1,100 by a buyer stating they got an empty box...signed fo0r delivery then filed a claim..the worst thing was the buyer sent me a message through them that they would "split the difference" with me. Who would take a $550 hit for an empty box???? I thought that was proof but no, $1,100 credit w issued out of my account. Unbelievable!
As it is, there is no incentive for the carrier to ensure a safe delivery, and the cost of that failure is spread amongst everyone.