Because their lives are a void, boring, empty, nothing to do. No interests except food and passive activities that are easy. So they go watch something and eat while they watch, must have food while they watch, though. Some, in my family are like this. Fat aunt must have popcorn while she watches a movie. It's sickening to hear her stuff her face while the movie starts. I stopped going to movies with her real quick after a couple times of that shit.