To be fair, various tabloids sometimes (although rarely) steal a march on other forms of media because they publish lots of salacious and unverified things while others prefer to double-check their sources. The problem is:
1) most forms of media aren't really verifying much anymore - they're busier than ever making sure nobody's offended or dealing with a pared back staff. After all news happens 57 hours a day! What the hell, issue a retraction or cloak a statement with "weasel-out words" like
"...on social media..." or
"...some are saying..." or
"...reports say..." or
"...allegations...".
2) even a blind squirrel finds a nut once in a while.
Also, I survived a 30-minute plane ride today; unless someone can prove a 100% clairvoyant record, there's precisely nothing that would prevent what happened without introducing another variable that could be just as unexpected and nearly unimaginable.
Air marshals? Who's to say he's not nuts?
Another lock - that could fail. Or the code gets released to those who shouldn't know it.
Bring back a flight engineer? Not going to happen with current cockpit sizes, although it
helped in this case. I doubt they want the babysitting, unless there's an available jumpseat.
Psychological examinations? Well, someone can lie really well. There's no way every pilot is going to get checked out each year along with the physical examinations, unless it's enforced - and the amount of false-positives that could spring from that doesn't exactly take care of the supposed pilot shortage. I think most know when they're out of their capacity to do their job, and every action and word is recorded (short of video recording) if they become questionable.
Unfeeling pilot robots? Let's get the driver-less car thing perfected first, okay?