I don't think that was much of the issue . I think overhead and time was the main issue. You could finish more jobs using subs. And yes, many of those subs had some Mexican labor. Quality in "some to many" cases became an issue as well. LOL....I never ran across a builder that had their own roofing crew though. F' that one. Same with hard coaters. Both a different breed man.
B402, The sub situation has accelerated in every country. That's companies shedding responsibilities, as you suggested. Since you know i gotta wonder why you still have no negatives to say about Trump's GOP.