American society loves drama, whether it be in the form of reality tv or just our every day life, we love to have drama in our lives. What else is there in our day to day that entertains us? Class? Watching TV? I doubt it. I always hear gossip between my girlfriend and her friends about so much different stuff, I don't know how she keeps it straight. But maybe this is just our perverse tradition of our need for drama, or maybe it is just a portion of our life that is unavoidable.
On the other hand, why is America so entertained with violence? America is not entertained by real violence, it is dramatic or virtual. If the majority of Americans were to see a person actually die in a movie, they would be absolutely repulsed. The networks know this so they gives us the dramatized and "clean" version. But we as the audience keep the dramatic violence and every day drama coming back because it is what we know and love.