Re: I can believe it!
Security is one possible concern. And simply discouraging printing, so people only do it when there's a real good reason.
Back in the days when printers (and 'puters) cost real money, it was also part of office management. Restrict access to trained staff. Admin/secretarial staff to pick up printouts and shove them in $user's intray.
Not entirely illogical. Open it to everyone, and someone is sure to mess it up. If not changing the toner, then trying inexpertly to clear a paper jam. Or something.