I think mass media is so much of popular culture (people don't do things anymore that aren't informed or influenced by it) that people think this IS the way culture/society is, and this is the way everyone else thinks and behaves, so they start behaving that way, then the mass media reflects more of the behavior, then people change their behavior to reflect what mass media is telling them, etc. and things ratchet their way over into depravity.
It's not as if they're going to listen to what their peers at church/synagogue or Kiwanis club or bowling club or sewing circle or Toastmasters think.
On another thread, people were discussing why people leave the church. One argument was that the gospel wasn't being presented with conviction and consistency and a lot of church leaders were more concerned with entertaining their congregation and being "hip." I've seen popular culture infiltrate the church to the extent that its ideas are swallowed whole and cloaked in cherry-picked Scripture verses to make them palatable to the congregation. Never mind that it's a worldly rather than a heavenly idea being presented.
Very sad but true.