There was a post above suggesting the NTSB is grandstanding. Their follow up letter (link in post 82) reads like a regulator doing their job.
If you want the NTSB to stop firing, stop handing them bullets.
51 foreign regulators (starting with the Chinese) grounded the Max after MCAS 2 before the FAA acted. So I do not buy the arguments above that foreign regulators are obliged to follow the FAA lead.