That's because neither of those 5* kids really had 5 star ability. Partially due to attitude and partially due to talent. They don't always live up to the hype. John Wooden himself couldn't get Sidney to the NBA, and while Malik has some tools he is going to peak out as maybe a decent college two guard. He isn't going to sniff the league.
And that is two guys in what, 20 years? We've gotten half as many 5 star players in two decades as UK gets in a single recruiting class. Think about that.