One group feed on the other. If no one watched this garbage, Hollywood wouldn't present it. And if Hollywood didn't produce it no one would see it. It's a bit like what came first the chicken or the egg. In 1939, Clark Gable shocked movie goers by uttering the word "damn." The Sopranos would have had no diaglogue if the F word that rhymes duck had been scrubbed from the script.
When something loses its shock value, it often becomes part of the common culture which has become crass and crude over the past 45 years.