Earlier quoted context omitted.
So, I'll put this into terms that a sysadmin can understand: imagine if all the Ethernet or fiber going to a datacenter rack was bundled up, and I cut that bundle up. Now you have to splice them back together so that every port is still connected to the same port it was before I cut the cables. Oh, and also, the cables are microscopic, incredibly fragile, and we don't know how to actually repair them. We sort of just…
The fact that they grow back in place makes the whole thing 1000x easier, no?
As another commenter posted, there are 31 "bundles" of nerves carrying a total of a few hundred thousand individual fibres. The odds of re-connecting a human spine correctly are simply incredibly small.