Yes, generations of Mac and Windows programmers have used GUIs to create their GUIs. Visual Basic, MFC + App Studio, .NET + WinForms, Interface Builder…
Why wouldn't you program a GUI with a GUI if one is available? Avoiding the use of WYSIWYG editors when making GUIs is like avoiding the use of musical instruments when writing songs.
Yes, generations of Mac and Windows programmers have used GUIs to create their GUIs. Visual Basic, MFC + App Studio, .NET + WinForms, Interface Builder…