Leaving chat on window close - is it a feature?

[Alexander Rokashevich]

When I close a channel tab on IRC/Jabber - I leave this channel at once.
Don't you think it would be more convenient not to leave it, just
minimize to "buddy" and continue logging conversations there?

I think that it is very convenient to have all IRC/Jabber stuff sitting
in the tray, without any additional windows on a window bar. But I have
never seen such a thing neither in Linux IM-clients, nor in Windows.

And I'm even thinking of realizing it myself, because it is the only
reason I use XChat instead of Pidgin.

Is it worth doing it, or it is done like it is because of some reason I
don't know?