I was just talking to someone about this the other day! I used to work in journalism, which is a business all about getting people to look at your stories. Unfortunately, human beings have a sort of morbid curiosity: bad news, i.e. scandals, murders, assaults, grand theft auto....that stuff sells. Good news doesn't bring hits. Also, in advertisement, you have to generate some sort of emotion to get people to buy your products. What better way than to generate anxiety? People do not want to feel embarassed, lost, scared: so advertisements are made just to say, "without this nice thing, you are lame" or "you will die without this thing!"
There is a lot of debate as to whether or not this is ethical behavior or not, but it is most certainly a thing we have to live with. I don't even watch the news anymore...I skim through stories to keep caught up, but news sites kinda depress me.