There's actually a chance that academics drove all this.
If JJ truly skipped an entire semester of classes, he may have been ruled academically ineligible for sports. He may have been put on academic probation.
Sure, it was the interim head coach, in consultation with the athletic director, who informed JJ that he's no longer on the team, but that doesn't mean they had a choice in the matter.
We won't know the facts until/unless they come out from someone inside the circle.
As long as we don't know, makes no sense to throw stones about.