Comment 5 for bug 246322

Usually root can always login to fix things on the console, unless you explicitly disable root login, and rely upon an unprivileged user running sudo, as Ubuntu does. So your "system non-functional" argument is surely a home-made problem.

Maybe it would be possible to introduce some debconf menu to enable this feature? The central configuration via dhcp options is in very wide use, especially in enterprise environments. I really would like to see this feature implemented.