Indeed. The whole "never run rm -rf" thing is so ingrained that someone I know took real joy in finally getting to legitimately use this to nuke an old server once the new one was signed off.
Pity he'd not considered that the old one had nfs mounts to the live data...
I think 'rm -rf /' shouldn't work and there should be special command instead of 'rm -rf /', something like rmrfhell, which would ask you three times if you sure and will tell you about pain and tears of other people who ran it.
Most versions have --preserve-root (fail if the target is /) on by default, so you have to use --no-preserve-root , although rm -rf /* will still work.
Pity he'd not considered that the old one had nfs mounts to the live data...