Being able to move a window wherever you click is actually pretty old (the oldest example I know of is the Aqua brushed metal type of windows in OSX 10.3 Panther, I believe). Compact window headers don’t seem new either. For example iTunes has this since 2010 (version 10).

[1] https://i.imgur.com/pCv8lV4.png

>everywhere that isn't another control

Is the list of messages on the left another control? It's clickable, but the whole thing is visually merged with the titlebar.

> Apple stole this design wholesale from GTK

This has been part of Finder and iTunes since at least 2006, at a point when it wasn't the norm for anything in GNOME2 that I can recall.

I think this is just reverting back to the way it was in MacOS 8 where a window could be dragged by the frame or the header bar - the only places where the chrome was exposed.

It's one of the design decisions in Gnome 3 that I don't dislike. Happy to see Apple adopt it. I always thought the combination of the Menu bar in OSX (top of screen) with GtkHeaderBar would save a lot of screen real estate... and seeing it in action is nice :)