Shows are divided up into those that are safe for children's consumption, and those that should probably only be watched by adults who can understand and mitigate the situations in the programs to their own beliefs and opinions.
But personally I feel that this issue is much more a concern than merely the differences between what a child and an adult should be watching. I think that television reflects what you want your society to look like. So, it isn't merely that television may reflect how society may be, but it drives each tendency a little bit more fervently, and definitely with more glamour than things actually are. After all, real life isn't 'entertaining'. A more extreme or dicey version of life may be though.
So, what does society expect the rest of society to be like when they consume and enjoy shows like "Two and Half Men" or "Sex In The City"? How about exactly the like those shows, where everyone is just out to find someone new to meet their sexual wants. Then from that show a person moves on to "Survivor" where everyone is playing fake friendship tactics to use each other such that they can get ahead in the end. Or how about "The Bachelor", where a guy gets to try out a ton of women to find which one is 'most compatible', make a huge deal about their love, and then divorce 6 months after they marry.
What do you want your society to be like? If you want it to be one where no one really has any actual friends, but rather one where people just use each other to meet personal goals...then television promotes that heavily. If you want people to sleep around everywhere in the quest for 'love' and 'compatibility', only to divorce nearly as quickly as people marry...television is your guide. If you want there to be a society where nothing is good enough, and you need to be staunchly individualistic, while simultaneously needing to be connected to a sexual relationship...then television has ample examples to help you.
But once those levels of depravity are attained in general in society, then those levels will no longer be entertaining on television. So, studios will have to push the moral questions and ethical situations...releasing programming with just slightly more shocking situations, or slightly more sexually depraved people. Then society will eventually emulate the situations they perceive to be 'normal' from what they see on television and movies.
This isn't to say that movies and television aren't reasonable mediums to be entertained by. I'm just suggesting that what should shock us doesn't. And behaviors that should seem selfish or sociopathic seem like normal life. Something is wrong with this, and perhaps what is considered 'normal' to people in general anymore actually is exactly what we don't want society to be. Perhaps this is why there is a complete absence of moral stories in television consumed by adults (or moral content is such an afterthought that most miss it).
I realize my thoughts in this writing are incomplete and slightly hyperbolic, but it seems to me that both the moral character of most television, and the character of people in society, are both on the decline. And this is considered 'normal'.