It is unusual to train some players and not others, however it is not unusual to have a focus to the training thus emphasising the training certain players get. BB gets half of it right, with the emphasis. What it needs is a second layer of training for the team that can be applied WHILE continuing the Focused Training it has now. There are many ways to do that, but that's not how it is here.
The point is still valid, however. Conside the Random Pops the players personal progress, his own training. You can't really stop it, he's going to train on his own anyways... every good player does. If he really wants to develop that Elbow Hook Shot, he's going to be tossing it up when ever he's not in practice with the team, working on it. Because that is what HE wants to do.
It's almost like giving these players a personality. "Hey coach, great practice today on Inside Defense! Real fun." Then he stays late and works on his own to fix his release on his Jumper. No Coach in their right mind would come in after practice, see him working hard on his shot... and tell him to stop, he might get better!
The point of the game isn't perfection... merely the PURSUIT of perfection. If these Random Pops make it where you can't get your Trainee PERFECT... AWESOME! Do the best you can to mold him how you want, and take what he improves on his own and apply it to your strategy. Use what he brings to the table on the court, that's part of coaching to.
All I am saying is people shouldn't cry about Random Pops. Real players would get better in areas the Coach doesn't emphasize, so why shouldn't these guys? And real coaches would try to use those skills to their advantage, so why shouldn't we? Instead of crying, looking at it as a unique and fun challenge. Probably what it was intended to be in the first place.