TV isn't the problem, in their rooms or otherwise. It's the good, solid, time invested parenting has gone on from the time the child is small. I have been teaching my children about good choices, morals, values and the concept of family first since before they could speak. Therefore, they are more than capable of handling most situations with ease and care...including making their own television choices.
It's is absolutely okay that my child has time on their own to do as they please. My dd for example is an honor roll student, has marching band which keeps her active and at school until 7pm, dinner with the family with long conversations, homework, showering etc each night. If she wants to veg out and watch mindless TV for an hour and relax...please do!
We put in a tremendous amount of time and effort into good parenting. During the teenage years I think it's important for them to also learn independence and that they are capable of making their own good decisions. These children will be young adults in college in just a blink of an eye. If you can't even trust your teen to handle watching television and making good choices about amount of time and appropriate shows, you have a much larger problem on your hands than a TV in their rooms.
I don't buy it. There are plenty of kids who had good, involved parents who have issues - and plenty of kids with parents who don't care that are successful. Good involved parents is certainly a variable, but like with anything, they don't get all the credit or deserve all the blame - neither does TV or the internet, or books, or genetics, or their peer group or anything else out there. I know, its frustrating to hear this - we want to think that if we do it right, its a guarantee of "good kids," but that isn't the case. And its a blessing to give up on that notion, because it means you don't need to take all the blame when your teenager gets busted at a party where there has been drinking.
What I have learned is that kids really go through a change as teenagers - even good kids of good involved parents - its normal and involves separating themselves from their parents. In my experience, a TV in the room has given then a lazy way to separate out, an excuse to not be involved. It has advantages - in front of the TV they aren't at a party drinking, but they aren't necessarily making productive use of their time either.
I'd encourage that anyone considering a TV in the room first sit down with all the adults involved (all including any steps or grandparents heavily involved) for agreement BEFORE broaching the subject with the kids - this is what we didn't do, my husband made a deal I wasn't involved in. The adults determine if the TV exists at all and the terms of usage.
Then, when the adults are in agreement, communicate with the kids.
Hold to any rules - if the TV is off at 9, its off at 9. If there are only x hours of TV in the house per day, then its going to be harder to monitor that with TVs in rooms, but monitor it. If you get veto power on shows, you get veto power. Or no rated R movies. If there are no rules, and your perfectly good teen suddenly starts watching inappropriate horror at 1am, because her new friend who is so cool has talked her into watching a movie "together while texting", you are coming at that problem from a position of weakness.
My daughter LOVES the TV, spends too much time watching it, but tends to watch "smart shows" - so its less annoying. She is also an avid reader and a natural learner - she isn't letting the TV limit her. For my son, the TV is the idiot box, he turns it on to turn off his brain - so he needs to be much more limited in what choices he gets to make and how much time is TV time. They are simply different children - little difference in how they were raised, but they are very different people (as a disclaimer, my daughter is our bio child and our son was adopted as a baby - so they are possibly more different than biological siblings right out of the gate - she inherited her parents intellectual curiosity, he seems to have almost none innate - but on the other hand, he is musical and athletic and the rest of the family has none of those gifts).
I did not have a TV in my bedroom until I was married.
In spite of all the other opinions here as to whether kids need one or not, I think this is first and foremost the truth. I don't like hearing parents say" I need to get away from my kids!" And I also cringe when kids say it too,on a daily basis,by escaping to their separate tv rooms. Chillout time? we all need some.... but nonstop,daily ,close the door and watch a screen by yourself time? It just feels so.....lonely.
We are the closest, happiest, loving family anyone could ever meet. We finish each others' sentences on a regular basis. We have 7 TVs in our home, and dont regret it in the slightest. There are times when DH and I want to watch something that the kids can't watch. If DD wants to watch PotC and DS wants to watch Power Rangers during that time, I have no problem with them going upstairs to their rooms to do so. Our favorite night of the week is Thursday, because it is "WIPEOUT Cookie Night". I bake chocolate chip cookies and we all pile on the sofa and have cookies and milk while we watch WIPEOUT. You don't have to be in the same room holding hands and singing Kumbaya 24/7 to have the perfect family. You do what works for you and if someone has a problem with it, they can take a long walk off a short pier.
So just because someone allows their child to have a tv in their room means parents can't stand to be around them?? You are really grasping at straws to make your point. 
