Coaches want to play every player. But minutes of play are earned by demonstration of skills. The more and better the skills...the more minutes.
Examples: Phi Slamma Jamma did not have 10 players of equal talent AND neither does Rick B NOR will any coach ever!!!!
But they are trying to work on defensive sets, and experiment with rotations, with player combinations, player development.
They are also concerned with player psyche and trying to put them in a position to succeed...and bring them along....
John Wooden promised one off his bench players (a senior) that he would start him next game, because he was going to quit the game. (Forgetting that is was a crucial must win game.)
So, to honor his promise, he put him on the other teams best shooter...thinking after a minute or two ...he would be so embarrassed he would be begging to come out. The senior actually had a once in a lifetime performance,...so it worked out. Coaches play them hoping the light will come on over the course of time. Sometimes it does, coaches always hope it will. Think KC last year..he got better during the season.
But more coaches are like Mike K, they play them minutes to help them develop, but players tend to develop skills in the off season. The floor is to help them discover why their minutes are limited. Their play on film shows them why their minutes become less.