All the listed people are in the legislative branch. The FAA is part of the executive branch. Short of passing a law that grounds the 737 MAX, legislators don't really have a say here.
Interestingly, Trump has also come out against the plane, but his uninformed Twitter ramblings are by and large (rightfully) ignored by the executive branch. And he's not against the 737 MAX for valid reasons, but for luddite ones.
Yep, Trump says a lot of really stupid stuff (like his comments about the electromagnetic launchers on the new Ford carrier). But in this case, even if his reasoning is stupid, it'd be better if the executive branch actually followed his lead and grounded the plane.
Just happened. Twitter ramblings rightfully go unignored, but a properly filed executive order does not.
Trump shares some blame here because he's never had, nor even appointed, an FAA commissioner. Maybe with someone confirmed in charge they would've been more proactive.
Interestingly, Trump has also come out against the plane, but his uninformed Twitter ramblings are by and large (rightfully) ignored by the executive branch. And he's not against the 737 MAX for valid reasons, but for luddite ones.