OP, you are simply wrong.
Juzang and Matthews played.
Matthews averaged 10.3mpg. And was not good offensively (44%/25%/41%). The 25% was only 1-4, and he was basically Ware at the FT line. He only played because he could play good defense. But he was backing up a very similar guy (also a FR) in Briscoe. So he probably arrived thinking Briscoe was OAD, and as a Soph he would step in, but then realized "Briscoe is better than me, but not good enough to be OAD", and that why he left.
Juzang averaged 12.3mpg, and it was higher than that (like 14-16) the last couple months of the season. And he was not tearing it up either (37%/32%/83%), the 83% was nice but he didn't get to the line much (12 FTA compared to 77 FGA). So he was simply afraid to compete vs the next class for PT. But also, MOST of the recruits from California, have transfered out since I've been a fan in the 80's, usually going back West. Hayes and Prince are the only 2 exceptions I can think of.
I'll give you Hopkins. And yes, the LSU game and then subsequent games, I can't blame him.
Livingston is getting his chances. And while he's had moments, he has also had lapses in those same games. Vs KU he had them on defense, but he also passed up wide-open 3's like he was afraid to shoot. You can't be afraid at this level. But we still have 12-19 more games, so lots of opportunities for him to have that 'break-out game'. I'd love to have CL and Edwards as our 2 forwards next year. Neither a PF, not sure is a SF either, both kind of 'tweener' Forwards who can take advantage of matchups. Those 2 with Onyenso (blocking shots) and the 2 FR guards, will be a good 5. Then throw in Theiro and Reeves and Fredrick and Collins and Bradshaw and Sheppard to backup.