Its a pain, say when you have 9 toons and you want to log in all of them to check on them.
lets take WoW for an example. it has 11million plus people who play it, regardless if you like the game or not I would say the security is pretty good. Why not have a password protected option for folks who WANT to have it log out to log in screen. or a
/login <toon name> option that would make it so you have to know your own toon name to log into it.