Pretty sure it does.

Does it not?

Non-trivial GUI-generating code can't be previewed in a GUI editor without emulating the entire environment. Styling also gets harder, and some concepts don't translate well into code (e.g. Grid.Column in XAML). Finally, retained GUI code should nearly always follow a MVC or MVVM pattern to keep logic separate from visuals, and a language barrier is one more way to do that.