What happens to a machine if someone never repairs permissions?

[Panopticon]

I only mess with it when creating a test drive on my fauxMac.
And that's only because I'm installing/deleting kexts, etc. Either do it
via CL or use OSX86Tools.app; I never use DU to fix permissions.

Though not related to disk permissions, this article has some interesting
info on OS X's maintenance.