I was not very happy when they decided to make Unity mac-like by moving the menu to the top bar. It has to be the most idiotic decision around for anyone who has multiple monitors. Even with a single monitor, it is a pain in the ass to move the mouse all the way to the top left corner for the menu to appear, and then orienting myself with the items presented.
It's certainly not perfect and I had some complaints with it (I like window-local menus), but they didn't make the decisions just because.
I thought that integrated menus are a great idea - even Apple does it. It saves vertical space and looks "at one" with the rest of the system.
Honestly 'even Apple does it' is a poor argument. If global menu would be a really good and generally accepted idea we'd see it implemented in GNOME and KDE (via extensions at least).
I am using KDE on anything I can, and I have no problem with them doing things like the global menu. KDE tends to get things right to my taste.