I don't watch many horror films these days, but I think you're absolutely right! I also think that watching a horror film home alone is particularly terrifying because there's no one to distract me. If I'm watching a horror movie in the theater or with a group of friends, I'll have one eye on the screen and one eye on the people with me, just to see their reactions. Maybe I'm the only one who does this, but sometimes people-watching can be just as entertaining as watching the film itself.