Maybe there's other church practices that help them? I get nothing from corporate worship (in the form of singing) most of the time, but occasionally I still feel like God drops a thought there for me in the midst of it.
I don't think we need to go quite to sin blocking the communication channels either. My most powerful prayers that I felt as though God prayed with me, were for others in situations that I know God cares about but I was powerless. I learnt about those situations because I was actively involved in ministry. We are in a war for our souls and contending for the souls of others. Prayer is a battlefield walkie-talkie we can't expect much of we use it to ask for a comfy bed and a pizza to be delivered.