Quoting Tomasz Torcz (tomek@???):

> So it would be sensible to ask for root password IF there are other
> (remote) users logged in. If there is no one logged in, shutdown/reboot
> should be possible without entering root password.

You speak as if the consequences of host shutdown (or reboot) were
trivial, but that is not the case: A local user who has shutdown the
host has terminated all processes (not just his/her own), and made the
entire machine unavailable to everyone.

Seen that way, I would hope you'd understand that by default shutdown
(and to a lesser extent reboot) should be a privileged operation.

Of course if your local usage model makes things otherwise, luckily it's
not difficult for you as sysadmin to give console users those powers and
whatever other powers you wish.