However, with VB business users who knew a database would come up with applications that served their needs well.
These applications are still all over many companies and government departments.
In general though, these folks wouldn't be able to do the same with XCode and in addition XCode only targets a platform that isn't widespread in business and government.
IB and EOModeller once too were targeted at business users. The RADsy parts of Xcode are older than VB. It's just a bit of a historical curiosity: while RAD tools went out of fashion (at least for 'serious' programming), Xcode is still ticking away, in mainstream use.
Still, things didn't get any more Rapid than they were in 1998 and that's a bit sad. In terms of productivity, C# with WPF/XAML is at best equally good IMO.
I would venture that WinForms is actually more RAD'ish than WPF.
A lot of that productivity came from the drag-and-drop form editing. And what made it possible (and easy) was complete disregard for any kind of advanced dynamic layouts. Delphi's VCL, .NET's WinForms and the nameless VB6 UI toolkit are all designed around the notion of widgets manually placed on a 2D grid, and the most that you can get in terms of dynamic resizing is "anchoring" their corners to containers.