It's the way of the world. Apple and Microsoft seem hell-bent on introducing "phone/tablet" type gestures into their desktop UIs also. It seems only natural that linux distros would follow.

Lesson for the kids making these decisions: "new and/or different" != better

No, Unity came before Windows 8.

And with Windows 8 noone actually used Metro, the real desktop environment wasn't really touched so you always had a polished desktop-oriented UI one key stroke away. Not so with ubuntu that single-handedly obliterated the desktop Linux market dominance it had.

On the other hand, browser mouse gestures were awesome for half a decade before smartphones were a thing.

Isn't it Gnome or the *dm? I use Arch with vanilla Gnome3 and it has the same drag up thing. I just press enter.

They did that because they'd caught the one-size-fits-all virus which made them yearn for Ubuntu phones and Ubuntu tablets. Those ventures did not really come to fruition but the side effects still show. Given the prevalence of touch-screen laptops it wouldn't surprise me if part of this idea actually does find a niche to settle in on convertible devices.

Never? It's not that hard to understand. To gain market share.

Current users aren't going to abandon it because of these various stupidities. The market they need to capture is the market that wants a look-and-feel-alike product.

Mostly GNOME is to blame for this.

Gnome is more keyboard centric than mobile centric.