It looks and works so intuitively.
The other was that the alternative to VB for GUI creation was wrestling with class libraries, at a point when OOP was utterly baffling to many casual programmers like myself. Just the bare minimum "hello world" kind of app on either Windows or a Mac was page after page of instructions.
I suspect that over the span of subsequent decades, demands on high quality GUIs have increased -- as mentioned by others. But also, the programming skills needed to build a small GUI using code have become more mainstream, maybe because the languages have gradually made it easier.
Today, for the quality of GUIs that I need, I'm actually happier to just code them, and let (in my case) Tkinter lay them out in an acceptable default arrangement. My victims, er, users haven't asked for anything better.