Edit: the no-fly list as a DHS entity, which I just learned about, is absolute horseshit. I assumed no-fly lists were per airline and I stand corrected.
Terrorism is an over-applied label that is used to stoke FUD and expand executive power; yep I agree with that and I don’t use the term lightly.
Joining an organized movement to overturn a legal democratic election, breaking into the capitol, armed, and bludgeoning an officer to death is terrorism and a private company has every right to deny these people the privilege of flying on their airlines.