I have to admit, when I hear the words "permanently disabled", I think of something completely non-recoverable. Like you basically just can recycle it.
There are a number of operations that you can do that make it difficult but not impossible to recover. For example deleting the system directory of the OS or flashing the BIOS with crap firmware (which can really suck).
If Apple is saying that hacks might nuke the OS and cause your iPhone to cease working that kinda falls in the "no duh" category of hacking. Tough luck to you, you will find zero sympathy from me. Most OSes don't really like it when you replace their key files with user-modded files.
However, I would expect that for a reasonable tech support fee, they should be able to wipe it clean and give you a shiny new system install.
I suspect as someone said, that this is as much a tough posture because of their current corporate relationship. I highly doubt they have tried to lock this OS down as much as people think. Personally, I think they are hoping folks will find workarounds but they can't make it too easy or appear too supportive.