That's the part that 56 never acknowledges. Players are only as good as the teams that recruited them, and most don't get that much better. For example, even when I pointed out a player like Bryant McIntosh (Northwestern) was actually rated worse defensively as a freshman than Jordan Bohannon (even though he said JBo was the worst defender he ever saw), JBo can never become as good defensively as McIntosh because he's 2 inches shorter and didn't have better offers coming out of HS.
I think that is a bit short-sided. I think JBo can get somewhat better on his own, and will also improve his defensive rating if the TEAM gets better defensively as well. Will he ever become great? No, probably not. Can he improve along with the rest of the team? Yes. He thinks there is no way they can become better than last year's team (starting 4 seniors and a junior) while looking at this team as mostly freshman/sophomores. I think that is short sided as well.
By the way, I do think Jok makes his teammates better at times. His assists (8 vs Purdue, 5 vs Nebraska, 8 @Michigan State) shows that at times, he is able to draw the defense and find open teammates for scores. Consistency is an issue (as it is with the entire team). That is normal for a team as young as Iowa.