Then what is the function CreateWindow in User32.dll for (for all non-Windows developers: this is the WinAPI function to create a control on Windows; it returns a handle to it)?
The vast majority of controls on any Windows screen in 2014 is created with CreateWindow calls with that parameter set to some value that was added on by RegisterWindowClass though.
I still agree with you that it's silly to say that Windows hardly has 'native' controls.