well it's retarded even if it conforms to Apple's monkey Interface FOR RETARDS Guidelines. If i close the main app window i expect the app to freaking quit period
You may call it a monkey interface but there are many Windows programs that do the same thing; MSN Messenger, WinAmp, and X-Chat just to name a few. In Linux you've got Gaim, Rhythmbox, the entire Notification Applet for the panel was designed to allow for this behavor. Hell, even every single Windows Mobile device doesn't close down apps when you "click the x". Why is that, I wonder?
There are plenty of reasons for an app not to close. For the most part, I like it because I don't need to have every single running program on my screen at the same time. I don't think of "the x" as closing a program, I think of it as just getting it off my screen. Minimizing is nice if I want to keep a specific windows contents for later, but something like a web browser I don't need on my screen or in my dock minimized and it is something I open and close all day long. It's nice to not have to load it every time; with it still running it opens instantly. Mail is open all day long, sending and receiving, and not on my screen. If I need to see it, it'll beep at me, otherwise get it off my screen.
I love this functionality. Guess that makes me a retard.