There's a variant of this fallacy where people are sold on GUI frameworks in which design is separate from the code that drives the logic (i.e. XAML). The argument is, the designers can't code, and the coders can't design. That too doesn't really work if you want great UI, and it complicates the lives of both the designers (tooling is shitty) and the devs (the databound visual tree code is opaque AF and therefore impossible to debug).