Screens for Hollywood campaign

Why is it that there is never a screen on any window in a movie or TV show. Walk up and down any street in your town and try to find a house that is not falling in on itself and find a screenless window. It won't happen. I've noticed especially on TV that whenever there is an open window there is never a screen. It doesn't matter if it is a beach house in Malibu, an apartment in Queens or a farm house in Alabama, no screens. So to a screen writers please add screens to the windows.