Yes, indeed it is.
Every single problem I've ever had with receiving an order, from anywhere in the world including China, has been with USPS.
I actually feel sorry for the vendors sometimes. They're not perfect and they can have problems too, but for the most part they receive our orders, send them out, their shippers get them over here and then the drama starts when USPS gets their hands on it.
Then we go wailing to the vendors about "WHERE"S MY PACKAGE" when they've done their job. What other business is there where the only party who is actually at fault bears none of the responsibility? USPS loses it and then sends us to the vendor, who has done nothing wrong, to eat the loss.
I have personal firsthand experience with this. My local PO scans it in never to be heard from again and then tells me.. "oops, sorry abut that, maybe the seller will send you another one."
Who else can get away with that?