More and more, the so-called experts have been taken the role of the parents over: teachers, psychologist, nutritionists, sports coaches, social workers and more.
If only it were so. I think it's the media that have taken on the role of the parents, not the experts.
Don't know if I agree about hostility though. I think violence has been a part of our arts since time immemorial, might even be the principal part of our arts. Take Shakespeare for example. Modern TV is child-stuff compared to the atrocities this guy dreamed up, and they teach him in all English schools in the world and he's one of humanity's best writers. So it's kinda silly to me when people say that, for example, Tarantino's movies are too bloody. Do they even know what kids read in schools?!
What worries me is not violence (according to Steven Pinker, violence has been going down steadily), but loose mores and ethics, especially regarding sex. It's the way we view other people that's wrong. The way people in Wall Street think it's okay to play with people's livelihoods and even call it dumb-money. That's what's most corrosive about TV and pop culture, I think, not the violence. The violence, if anything, has a cathartic effect, like ancient Greek tragedy.
I personally raised 5 children. The eldest daughter was born when we permitted television in South Africa in 1974. What you say about declining mores and ethics is true. However, this is not only assisted by the media but the effect on family life, family relationships and the destruction of the importance of belonging to a family, support groups and acceptable norms is the main reason behind the collapse of western civilization that we have become accustomed to since the industrial revolution. it was the belief in the goodness of the western world, Christian homes and the human faculty of opposing evil that won wars in the 20th Century. The Cold war with its physical walls and psychological barriers continue to erode the good humans are searching for. Unlike the ancient tragedies you refer to, modern man-made tragedies eg genocide are immediately reported worldwide. This global exposure plays into the hands of the mad people who perpetuate this behavior. The focus is on me, myself and I and increasing the wealth of the perpetrators of these heinous deeds. Belief in a God who is omnipotent is on the wane - to the degeneration of our world that we have fought for and developed into the 21st century.