Not that I would have expected anything different considering who posted
it in the first place.
Thus Debian kernel team should be blamed for that misbehaviour. Don't worry,
hardlinks behave just the same way, as you describe. Use authentic Linux
kernels, if you dislike that.
Just tested it on my colo where the provider is using some homebrew
derived from the upstream Linux kernel. In any case Pavel was most
likely using Suse and I asked someone to give it a go on one of all
Ubuntu varieties. So even if it is not present upstream it is in a patch
which more than one distro has adopted (f.e. ptrace fixes).