Seems like the PR war is in favor of the airlines.
If you refuse the follow a flight attendant while airborne they can easily return to the point of origin or the like and bring the Fed Hammer down on you for fucking with an aircrew/operation of the plane. Or just have the Feds waiting for you when you land. Or if there is an Air Marshal on board you might get to be cuffed to a seat someplace in the back.
At least you’ll probably get charged with interfering with is like a $25k fine.
If the airlines want to be harsh on you, they’re probably going to succeed. Especially if your defense is “muh freedums”.
There are vagaries, but generally after 9/11 “refusing to listen to the crew” is something you don’t want to do.
Hell, odds are fairly good the other passengers might tackle you and beat the shit out of you.