It's hard, b/c even though Kizer probably could have used another year in school, he was, almost across the board, projected to go in the first half of the first round in mocks and draft rankings that came out during/immediately after the season. Presumably that's what he was hearing from his own advisors, too. So it was hard to argue there was much financial upside to him sticking in college for another season. Hindsight is always 20/20 on draft day but surveying the field in December he probably made the logical choice.
Of course, if he does fall (like various ND and other high-profile QBs before him) maybe the lesson is that mock drafts made before the combine and interviews and even before you know what teams hold what picks are little more than garbage clickbait. Actually that probably is the lesson.