Why kids shouldn't watch tv

We really don't let our kids watch much tv. There are a few educational shows we tape for them and there a few movies we let them watch. Well lately Jason has been letting them watch Star Wars, with some censoring of scary parts. So now the kids run around pretending everything is a light saber (is that how you spell that???) Which is fine, they don't hurt each other. But why oh why must they always make Jacob Darth Vader (goodness, is that how you spell that too??) They call him Darth Vader and then run screaming from him. They're going to make him have a complex that everyone should run screaming from him! Hopefully this is just a phaze and they move on to something else soon.