This discussion raises a pet peeve of mine, in this field. I think it's relevant here. Many modern revisionist explainers seem to think that the people investigating weird or even just mysterious events in the past were somehow less intelligent or rational than the modern armchair "investigator" or blogger or what have you. To me, the idea that the people looking into such things at the time of their happening were somehow deficient is about as rational or intelligent as claiming the ancient Egyptians couldn't possibly have built all that stuff without the help of, to put it bluntly, "white people from space". UFO investigators in the 40s and 50s seem to get this treatment more than most. Back then, such people were often professionals of one stripe or another, and if you actually go and read what they wrote back then, it's obvious they were careful, logical thinkers who spent time with witnesses, studying whatever evidence was left, querying weather records, calling up airport personnel, and so on. Exactly the sort of thing not done by the typical internet sleuth.
The disappearance of Flight 19 is unexplained, simple as that. To the people doing the searching immediately afterward, it didn't make sense. It still doesn't make sense. Probably the planes are in the ocean somewhere, but we don't know why. Revisionist explainers like to say things like, "Well they were inexperienced pilots who got lost in the fog." Never mind they were not inexperienced, and there was no fog. We all need to sleep at night, and some of us can't do that knowing there are mysteries out there that might not have "logical explanations".
Amelia Earhart's disappearance is unexplained too, but the situation was vastly different. She was on the hardest, most dangerous leg of a flight that was just about doable. Her plane is probably on the bottom of the ocean too, but it's hardly surprising. She was not adept at using the technology she had at her disposal, and she was trying to find a speck of land barely big enough to land a plane on in the middle of the Pacific Ocean. It would, perhaps, have seemed more surprising to us if she'd made it. Read about that nutball Lindbergh and think about what his chances of success actually were. He was at least as much daredevil as he was brilliant aviator.