My point being that KDE doesn't need these extensions for what one might (as a beginner coming from Windows) consider essential functionality. I don't even use any non-preinstalled/third-party KDE extensions but I am using an extension for tray icons whenever I use GNOME, because it's just a fact of life for me that I use applications that make use of a tray icon where I don't want to lose the functionality. It's not about "GNOME extensions break while KDE extensions don't", it's just more likely that a beginner would want to use extensions with GNOME and is probably less likely to want/need them with KDE. Context matters here :)
I also never said that GNOME is worse, just that KDE is probably better for beginners because the default out-of-the-box configuration is more feature complete when you expect certain features Windows has - which, like it or not, is where most beginners are coming from.