If you look at it from the courier's side it makes more sense though.
It's obvious if an item was new and you can safely assume it was the delivery company that damaged it.
Whereas for secondhand items there's no way of knowing the original shipping condition. And it would open up massive amounts of fraud where people would buy a cheap broken item on eBay (sold for parts), ship it to a nearby friend with full insurance, and then claim the shipper broke it.
Insurance should still cover the case of an item lost in shipping however, regardless of new/secondhand, since there's no opportunity for fraud there.
It's obvious if an item was new and you can safely assume it was the delivery company that damaged it.
Whereas for secondhand items there's no way of knowing the original shipping condition. And it would open up massive amounts of fraud where people would buy a cheap broken item on eBay (sold for parts), ship it to a nearby friend with full insurance, and then claim the shipper broke it.
Insurance should still cover the case of an item lost in shipping however, regardless of new/secondhand, since there's no opportunity for fraud there.