Ubuntu 14.04 default settings do the same thing Windows does -- make resizing grips well beyond the outer edge of the window -- which is incredibly annoying, because 1) it interferes with the content and/or edges of adjacent windows, which I sometimes want to interact with (or resize to be closely side-by-side), but can't because it keeps grabbing the resizer of the window which I'm not even clicking because, 2) it has defied the physicality of the environment (this is what I referred to as the "insanity"), and established a new paradigm to the user that there are "invisible regions" on the screen which are actually sensitive to input.
Zero-width window borders (with a nice soft shadow) manage to provide maximum screen real estate
No, they don't. Did you understand what I wrote? There is no more real-estate available than normal "thick" borders because you don't have use of those 4-pixels that extend beyond that "thin" edge -- i.e.. where the shadow is. That's your "fake thick resizer". Its visually deceptive and totally interferes with usability when one is working with multiple windows. But hey, who ever works in multiple windows right? Taht was my point about designers dumbing interfaces down to "one app at a time like a phone or tablet"..
So they give a false appearance that they're "thin", they've crossed a line that had not crossed before -- they took the physicality of the system away in favor of "magic invisible regions".
Plus, it is now ambiguous with windows that are not resizable. Remember when it was only non-resizable dialogs that had the thin border? Before, there was that visual cue, now, its ambigous.
IMO, its a big design mistake that only ever gained any acceptance because of its "eye-candy" nature. Imagine if they tried to pull this off without a soft shadow, but with a simple translucent rectangle like Squeaks classic shadow -- I think it would never have been accepted over thick borders because it doesn't look pretty enough..