I understand where you are coming from, and don't disagree with you, but we aren't just talking about parents teaching their children.
It's perfectly reasonable for a parent to decide their child should spend time away from computers.
It's also very easy to take this reaction too far. Deciding what a child should do with a computer, or even that a child should not spend more than 10-20min. at a time using a computer seems reasonable, or even necessary to a lot of parents. Such a situation would have been extremely detrimental to my childhood.
It's easy to overcompensate for things like this, just like it is easy to overcompensate for safety. Parents who know better are likely to ignore studies like this, but others will definitely use these studies to excuse their own draconian censorship, privacy violation, etc.
> This is also why sex ed is important, BTW.
Correct thoughtful sex ed is important. Teaching children to stay away from or fear their sexuality is detrimental, yet it is still common practice. It would be nice to be able to expect a reasonable reaction from everyone, but the fact is that we simply can't.
I think the focus of studies like this misses the mark. Children need variety, so it's important for parents to push them out the door from time to time. Unfortunately, a lot of parents find it more important to schedule every moment of their child's life, make every decision for their child, or be somewhere in between. That attitude leads them to awful things like censorship, and privacy intrusion.