Two words: regulatory capture. I very much doubt that the career engineers and administrators at the FAA chose to abdicate the responsibility, but there are all

Two words: regulatory capture. I very much doubt that the career engineers and administrators at the FAA chose to abdicate the responsibility, but there are all sorts of ways that politicians and their appointees at the top can bring this about without an explicit policy: reducing headcount and reassigning staff, rewriting the low-level rules and guidelines, burying the staff in paperwork and meetings... Boeing can also subvert the process by disputing every point, administrative burying, and by concealing things (such as the increase in MCAS' power to change the trim after the initial version was found to be ineffective.)