Control is one issue.
Another is that we have become inured to the day-to-day tragedies around us. We hear of the car crashes, etc., on such a frequent basis and we know, at least on some small level, that someone's world has abruptly changed.
When a plane goes down we feel differently because we've spent so danged much time in them ourselves -- we can relate to it on a more visceral level? Plus the tragedy is magnified by oh so many times. So many lives affected in an instant -- it somehow sinks into us much more deeply than the "regular" mayhem of modern life.
IMHO
Marty