Username or EmailPassword
So clearly for some people it is fine, and for some people it is not. That's always the case; software tends to be judged by the worst-case though (as it should be), because those are the cases that still have to be fixed.
There's no need to maintain that everything is perfect in KDE-land, there are sore-spots just like in GNOME or any other software project.
Software is complicated and can fail in very interesting and diverse ways, especially something as big as KDE; it's hard to get perfect.
Some errors will be due to KDE's dependencies, some not, but who are you to say that they're all due to dependencies? Good thing the KDE devs don't think like you, nothing would ever get done. All bugs marked "Works for me -- CLOSED", that'll work really well....