We generally don’t draw drawings by issuing commands so why should we draw a GUI using commands? To me designing a GUI is an inherently visual task where you want the immediate feedback a visual design tool can give you.
I know people differ strongly on this, but the ones I encounter who don’t care for visual tools tend to be very software engineering go oriented people with little appreciation for the craft of good visual design an aesthetics. Whatever is more practical for them to program.
If you want a great looking GUI and don’t use a graphical tool then you are just going to add an extra step to the process where you sketch it out first in a design tool like HTML folks and then program based on that design later. Sure that is doable but also adds another step that slows down your whole process.
It means designers and developers have to use entirely different tools.