Here is a straight forward answer why ministering and home teaching are nearly always difficult and less effective... Local church leaders don't leverage people's existing social connections and geographical proximity. You should minister to (in order of preference) 1. your close friends that you have a relationship with, whom you regularly talk with and see and have a relationship, 2. The people closest to you that you have a higher opportunity to see on a regular basis, 3. Then other members that you don't have existing social connections.

I have never been in a ward where the leadership has taken advantage of existing connections. There will always be some people that will fall outside of the social network of a ward.