We saw last night why Johnson isn't playing. Gave us little or nothing in his brief appearance on either end.
Let's leave the rookies to Doc, and quit conflating their highly-questionable abilities, ummkay?
So a person gets 2 minutes of playing time once in a blue moon and you think every time he comes in he should look like KG or something? How can you question his ability when you haven't seen much of him at all? When he had a chance to play a lot of minutes when Bass went down, he played well! Earlier this season when AB was getting hardly any minutes he look downright abysmal! When Doc was forced to play AB, what do we get... a solid rotational player!
Actually, Doc was giving minutes to Avery Bradley from the get go. When Bradley "didn't look good"(in other words was missing most of his shots, because his defense has always been stellar).
When Rondo went down he chose Bradley over Dooling and Daniels to start at the point. he defended him when he was missing shots saying they would eventually fall because everything he had seen of Bradley in practice showed Bradley could make shots. So because of his excellent defense and Doc's confidence in his offensive abilities he stuck with him and Bradley developed.
JJJ obviously is not showing enough to off the court to instill in Doc the same confidence that Bradley was able to give to Doc with his off the court play.
This is the thing SO MANY CB POSTERS DON'T GET. Players have to earn time through what they show off the court in order to get on the court. This is a time honored tradition all the way down to high school basketball. You don't get playing time to prove to the fans that the coach is right or wrong. You earn playing time by impressing the coach with your game off the court and keeping it with what you show on the court and screw what the fans think.
Doc isn't obligated to prove to the fans that his decisions are correct. He has a long history showing his decisions are correct in developing talent. When players have earned their way onto the court they get on the court. When they haven't they don't.