Well, it may be a consideration, but certainly not the only one. Kids like a lot of things that aren't good for them. If kids like playing on the highway, should they be allowed to do it? Some of the things they are exposed to on television are just as dangerous to them mentally as playing on the highway would be to them physically, but most parents seem far less conscientious about what their children put into their minds.
One of the things I see too often is young children who are acting out sexually because they've been exposed to pornography. The common parent explanation: "we didn't think they were old enough to understand what was going on." Well, they might not be old enough to understand it, but they are certainly old enough to be intrigued by it AND to act on it.
Certainly liking something IS a criteria, but it seemed to be her ONLY criteria. If he liked it, she let him watch it, because if she turned the channel or put something else on, he'd pitch a fit. I know. I was there. It was really pretty sad.