So this was something that came across my mind randomly: why shouldn't normal members be able to hide their online status? It seemed like somewhat of a privacy concern if people can't browse the site without having the ability to do it literally privately. Well, to a certain extent. Staff members can still see you, but non-members can't and I think that's what matters. That being said, I got the OK from the other admins to flip the switch. Enjoy this highly unused SMF feature while you can.