If anyone ever declares that billionaires got so wealthy because they're so much inherently smarter than everyone else, just remind them of this debacle.
Now now, let's not jump to conclusions here. It's also entirely possible that they are dying on the surface of the ocean because the owner of the company opted to bolt the sub shut from the outside rather than design an escape hatch and chose not to add a locator buoy after the last time they got lost.