[wellpast]

Aren't statically typed languages "sound models"? Aren't ADTs a form of data structure?

I think his point is much more in the realm of abstraction. RH always seems to be trying to minimize the delta between thinking and coding/problem-solving. ADTs are in most cases cumbersome. Static languages introduce more impedance and coupling than benefit to the industry business problems we're solving via code. These are arguments against certain attempts at abstraction, it seems to me. But I may be missing what you're saying.