Just from my experience in churches up till now (I've been going since I was conceived) it seems to me when the reigns of the entire church are handed over to a pastor, he either gets big headed or overwhelmed. The pastor is supposed to be the spiritual leader and also a person the lay-people can go to for guidance and biblical teaching. If the pastor is busy with 15 projects the church is working on at once, he could either become a control freak or just burn himself out. When pastors get hard-headed, people in the congregation get hurt, when he is overwhelmed, the pastor gets hurt. I have witnessed both instances personally.
The most effective pastors I have met are the ones who let the elders and others take care of peripheral ministries in the church. They, in turn, were more prepared to teach and council people.
So should pastors just preach and council? No. As I said, he is the spiritual leader in the church. His managerial position is to make sure people are growing spiritually.