They know what the questions are. This is the most meaningful educational experience I have had in my 40 years of teaching. It is tough to teach preaching to those who have never had to do it. The most you can do is to help them put a sermon together that is clear. So seminaries do share a bit of the blame, but there is a difficulty at teaching good preaching at the seminary level.
Good preachers become good preachers outside of the seminary.
That is what is unique about this program. This is a two-week program, but there is a lot of reading they do prior to the course, and when they leave there are projects they have to do in their church. To get lay people involved in evaluating their sermons, and involved in the preparation of their sermons. To raise the questions that a layperson feels needs to be answered. So, implicit in what you are saying is that there is something fundamentally flawed about the way we've prepared people for ministry.