10 has ADHD, and he's easily distracted. We have always read to the kids at bedtime, but with 10, when he outgrew us reading to him, he wanted a different bedtime activity. This turned into watching one particular show, but when there aren't new episodes, then he wants to do something else. It just kind of grew into a monster until I recently put my foot down. He can do a quiet activity before bed, and we will tell him when it's time to brush and change, then we'll tuck him in.
A lot of it has to do with him just wanting to do something with a parent, which is mostly ok, except that it got out of hand.