Why have icons where the people can't see them?

I gave a tour of my church today, and as I was giving the visitors a peek behind the icon screen, a gentleman asked if other churches had more diaphanous icon screens, so that people could see the icons behind the altar. I said that some in fact offered less concealment, but I said that we must be cautious. Not everything in liturgy needs to be seen by the people. To have that mentality is to shift the focus of the liturgy from God to us--liturgy as entertainment. 
It is not a bad thing to have icons that are never seen or prayers that are never heard, since the liturgy is not for the sake of us and our entertainment, but on God and our thanksgiving for the blessings given.