How many people actually do that? Not many.
I can relate, though. It can be quite annoying not knowing if someone just slacked off but will return shortly/eventually, or is REALLY gone and not to be back for some hours...
But I suppose this can't be helped, so w/e.
You could always prompt people to hit the actual LOG OUT button - how hard is that?

Or just not use the 'always stay online' function...
