So here it is! How about a system that allows you to SIC asleep characters such that you can't tell whether someone is logged off or not, since not all logged off characters are ICly asleep?
Just because a given alias is not on "who" doesn't mean the character isdisconnected. Or even in brownout.
The idea sounds like a MUCH bigger pain in the ass than the problem it's aimed to solve. 50% of all game activity would turn into "Didn't you get my message?"
Putting disconnected players' characters on "who" seems wrong.
Of course, then you turn from one suspension of disbelief to another, as you'd have to forgive players for their characters' having been busy doing something else and being unable to respond to SIC.