Very true - I think it is so important, especially when they're quite young.
I am not sure how it was with me, but I was a very insular child and I also had a problem with feeling empathy or relating to others at that age, right up until I was around 10 or 11. Nobody recognized it or tried to help me with it, I think it was concluded that 'that was how I was', but the good thing was that my parents always took the time to answer my questions and to explain to me why I should not do things, rather than just saying "don't." And, luckily I guess, I respected them absolutely. But I didn't get much time with them that you could say, was 'affectionate' or that taught me how to bond with people in a way that means you bring out the best in yourself and in them. It was an intellectual upbringing, but not really one where I could say I 'felt the love'. Even now I respect my parents but I don't feel very close in the way I see other people can be.
Funny, I respected my parents implicitly, but I didn't really understand at that age why I should feel the same about other children, or strangers. To me they were just 'outsiders', and I didn't see why I should have to impress them. So school was a pretty unfortunate experience for me.
Since nobody really 'helped' me with any of these things, it took a lot longer for me to get to the level of other children socially in school... my grades were good, but my social life was abysmal. I managed to sort it all out by myself in the end, but I was so far behind I'm a little angry at my parents for that because I spent a lot of time back then anxious and unhappy and unable to relax. But at the same time, they let me become who I was without trying to force me to be one thing or another so... I can't blame them really. But because of those experiences, I know that how a few crucial years in the beginning can totally affect the the kid's life and outlook... maybe for the rest of their lives? Knowing what I know myself, I'd be very careful of it if I became a parent. Which is my my sister's attitude really bothers me. I don't think it's the games themselves, or the movies or anything like that that is the real factor, it's the dominant human influences in the child's life. If the parents are emotionally absent, that dominant influence could then become peer pressure, or it could be that the kid withdraws into those kinds of escapism and learns their world view from games and films and stories, without much of a counterbalancing POV. But like you said, it totally depends upon the child and they are all different. Some cope well and others really need help. It's just a shame to see when they don't get the help they need, or to see kids with horribly neglectful parents.