Doesn’t this reflect draft strategy. If you are always going for players that are HS kids with big upsides and commitments in hand this situation will occur. Only one of those players were picked before the 7th round.
Of course there’s another version of “the one that got away” — the future superstars who were drafted (by others) lower than the “sure thing” guys who turned out to be busts. But even if you restricted yourself to just first-round busts, that list would be huge for every team.