How come not 1 player who played High School Basketball at Mater Dei in Southern California, has gone on to?

have a long, decent career in the NBA? I'm talking about Mater Dei High School in Santa Ana, Orange County, Southern California. They are without a doubt one of the best High School Programs in the Nation, and definetley the best in California, they win win win win win win win win and WIN!!!!!!!!! WITH A CAPITAL W!!!!!!, sorry just being sarcastic, not trying to rant. Their Head Coach, Gary McKnight, since he became Head Coach in 1982, his overall record is 892 wins and 81 losses, they have won 20 CIF Championships with 24 or 25 CIF Finals appeareances and 8 State Championships with 12 State Finals appearences, and about 140 players have gotten Major Division I Basketball Scholarships, only 5 or 6 were drafted by the NBA but they got cut by their NBA teams immediately. I'm not saying that they have to become a Superstar in the NBA like Kobe, Dwyane Wade or LeBron James, but at least become a bench player, a role player, but not even one player from Mater Dei has lasted in the NBA.