Lay down the pipe, it is their fault.
It's really not the manufacturers fault. Common sense dictates something as heavy as an air cooled 4090 / 4080 / 4070Ti / 7900 XTX / 7900 XT / etc. should have some sort of support to prevent the PCB from flexing if it's going to be installed in the traditional horizontal orientation.
Common sense further dictates that moving a system with something that heavy still installed in it with no additional support and thinking there is no possibility of something breaking is absurd. It would be the manufacturers fault if these damages were caused by a manufacturing defect, but they're not. They're caused due to damage from shipping or individuals either known or unknown negligence by not installing something as simple as a $5 GPU support for a exorbitantly more expensive piece of hardware that every warranty states will not be covered in the event of physical damages.
As I said before, manufacturers should advocate more in informing end users that they should install a support bracket for most cards that are 2 slots or more but that doesn't necessarily put the blame directly on them. If every PC case was designed so PCIe hardware was mounted in a vertical fashion these incidents would be almost unheard of. I don't see you blaming case manufacturers though.
There have been plenty of cards purchased that come with a support bracket for this exact reason and the end user opts not to install it anyways, how is that the fault of the manufacturer? There is only so much engineering that can be done to combat breaks like this when the GPU is mounted horizontally with zero additional support.
The only ones who need to put the pipe down are customers who feel they're entitled to warranty repairs or replacements for damages that were ultimately their fault. That's not how warranty works, it covers manufacturing defects and premature component failure, not cracked and broken layers of fiberglass epoxy filler and copper from customer negligence.