For kids, whether it's a good idea or not depends on the kid.
We put a TV/VCR combo in ds's room, he's 4.5. It doesn't have cable, he can only watch the 5 or so VHS kid's tapes that we have. He's a VERY early riser, so this gives him something else to do in his room when he gets up to allow us a little more sleep. He can read the clock, so if it's after 5am he is allowed to get up. If it's earlier he must go back to his bed. And he can wake us at 6:30am.
He's good, he never asks for it at night, or on the weekends. It's never a problem to turn it off when we get up and get ready for school/work.
If it did become a problem, though, I'd have no issue removing it. Dh and I agreed to try it and see how it went, and for us it's working well.