First of all, GTK3 and its underlying GLib library are pure evolutionary compared to their predecessors. Some 98% of GTK2 code can simply be recompiled almost as-is for GTK3. All the old GLib middleware functions are there, and in fact, GLib never even had a "3.0" release -- its version number is still in the 2.x range, so they haven't even broken ABI.
Gnome 3's features are in direct response to repeated user requests for a desktop that can takes advantage of today's 3d graphics cards (the more long-standing request), and also which can work well with a touch interface (the much more recent request, which can be seen by e.g. users of Ultrabooks, which are x86 thin laptops with a keyboard and a multitouch screen).
I'm sure that if you were using an Ultrabook, you would agree that Gnome 3 is more usable than Gnome 2. So what actually happened is that Gnome changed its target market away from traditional desktop users, towards mobile computing and touch interfaces and people who like eye candy.
This is, naturally, going to alienate people who prefer to interact with their desktop primarily using a keyboard and mouse, and who don't give a crap about eye candy. But the perceived demand for eye candy and touch interfaces is so overwhelming that, essentially, Gnome doesn't care that people like you and I are still wanting the old interface.
Well I'm sure some of the contributors to Gnome care. But overall, sacrifices in the design have been made, in order to please touch users / small screen users / mobile users, to the almost universal displeasure of workstation users. That's just the way it is. It's no big conspiracy; it's just that the projects naturally want to support the user base that is going to have the most users... and they think that is or soon will be people on mobile devices / tablets / ultrabooks with touch interfaces.
BTW, Red Hat is one of the main contributors to Gnome. You can bet your arse that RHEL 7, which will be based on something like Fedora 16 or Fedora 17, is going to ship Gnome 3 (because that version of Fedora does). Tough luck. You'll just have to keep using RHEL 6 forever I guess, long after its 7 years of security updates have expired...