their components have precisely the same interest; money ...
just in case you did not know a bit of shocking news for you ... money is very much part of the recommendations after any such investigation. It is actually the FAA that makes monies calculations. NTSB could for example say we want you to make all wiring made of silver (better conductor) or double the number of emergency exit doors, FAA will take it and study whether it makes sense in terms of finances, by law they have to use around $2 mln (could be higher today) as a value of human life. There is a long history of FAA ignoring NTSB's findings or recommendations. NTSB is supposed to be this "mean" cop and FAA should be more on the aviation industry side, so here is more room for you to spin even more conspiracies.
. The NTSB of today is not the same NTSB of that time.
You are entitled to your opinion but I see little evidence of that. Sure personalities come and go but I see no change in the overall expertise and competence.