If you talk about Gnome1, about experiencence and a COM-based technology, I would agree with you that resemble to one level Windows 98 experience and libBonobo was a somewhat distant ressemblance with COM and COM+. If you talk even as orientation of Apply/OK/Cancel buttons, they also look like Windows.
Going forward to Gnome2: Gtk2 have more abstractions like a true Model-View-Controller implementation used in a lot of places, libBonobo was reduced to dissapearance, and the libHal based to intrinsics of DCOP KDE implementation.
About look&feel? I think OS X is a better matchup.
What about Gnome 3? Probably is too early to say true directions: look&feel - still OS X/iOS, minimalistic buttons - still OS X. GObjectIntrospection looks as any reflection API, probably a hook from Java world. Programming with Vala is way off either Win32's API, MFC, Windows.Forms but luckily seems very close to GtkMM or Mono + Gtk# implementations.
But your analogy stands ground. Mono have similar origins (Miguel), which stars of from a Microsoft technology, but is divergent in many points. Also, as said by myself two posts earlier, Mono is not on catchup, but on entering in new markets and to catchup from other fronts, as multiplatform (including iOS and Android), embedding, alternate support for Silverlight thought Mono.
So as value of truth what you said is true: Gnome probably resembled with Windows initially but it grows as a different beast, the same about Mono with .Net.
But comparing as face value, Qt looks and behaves very much as Delphi/CodeGear/Embarcadero Delphi/C++ Builder. And the experience of KDE applications is very Windows like. And true programmers that use it, will be overwhelmed by similarities.
At the end: why to be so afraid of Qt in 1997? Was just a proprietary toolkit with a GPL only license that you can create almost everything excluding something to sell? Gtk+ even as crappy as it was, catched up in many ways, excluding programming paradigm. Thanks to Vala is not true anymore. To not say about look&feel: is Windows: your Dolphin and your Konquerror were better matches to Nautilus as Windows Explorer copies. To not say that to look for any settings you go to Tools->Options instead Edit->Preferences as in Gnome HIG. Too Windows like, isn't it?
At the end analogies between Gnome and Windows seem pointless, as a Gnome user I feel offended. I am just appalled how KSC look Windows like but I do no fuss. Plasmoids to recreate the desktop anyone? That look as copycats for gadgets/widgets? Look for a Gnome 3 like solution for the same nonsense. Or maybe you found them in Unity... I doubt it!