More generally (and less insultingly!), any programmers who mostly work with frameworks, rather than writing solid chunks of their own code.

I had a job building e-commerce websites on top of a framework. Our code was a thin layer invoking and customising the framework. It was difficult work that we charged a lot for, because it required extensive knowledge of the framework (which was badly designed and poorly documented). But it never involved thinking really hard about programming itself.

I would imagine most Rails programmers are in a similar place.