GNOME 3.8 released

I disagree with you on that point and agree with the OP, an officially blessed Classic mode (not called "fallback") would have done a lot to assuage most of the complaints and frustrations that plagued the early GNOME releases although you are right that it wouldn't have changed some of the UI issues you are concerned about. A lot of the complaints were that the UI was just too different, Classic mode fixes that.

Of course it's all speculation because that's not what happened.

I've been trying out Ubuntu Unity and GNOME Shell on an old laptop and I wasn't expecting it but I actually like GNOME Shell more than the more traditional Unity (definitely more than KDE which just gives me the heebie-jeebies for some reason, and I actually used KDE 1.x-3.x as my primary desktop for many years).