Aviation runs on trust. You trust the mechanics to do their jobs right, you trust the dispatcher who plans the flight, you trust the ATC controller handling your flight, you trust the security screeners to keep weapons off your airplane, you trust the cabin crew to do their jobs properly and you trust the person in the other seat to know their stuff and operate the aircraft safely.
It is an amazing thing that we often climb into cockpits with total strangers and yet have an aviation safety record that makes the drive to the airport the riskiest part of the journey.
Sometimes, the system breaks down, but these are exceedingly rare occurrences. Aviation remains an extraordinarily safe industry despite the incredible complexity of the aircraft and support systems that keep us flying.
9/11 prompted a massive overreaction that changed the industry and job for, IMHO. the worse. It would be tragic if this event did something similar. What would be even worse is if the trust that keeps everything running was undermined, particularly since this seems to be the kind of "black swan" event that by definition is at the tail end of the probability distribution.
When I hear talk of mistrust of cabin crew, "airlock" doors, armed marshals and the like, I cringe -- and think about early retirement. I chose aviation because, like most, I absolutely love flying airplanes. Retiring from flying and using the law degree I have may be something I need to consider if things get even worse than they are because this prompts yet another ill-considered overreaction.
To truly live is to accept a certain level of risk and the elimination of all risk is an unattainable fantasy.
But, to sum things up, this remains, despite it all, a remarkably safe business, which is a fact that is often lost when incidents, whether accidental or deliberate, occur.