I think that a lot of it is due to that fact there are so many shows and movies produced today. Back in the 30's, 40's, 50's, and even 60's, all you had were the movies, radio, and then network television. Today massive amounts of entertainment are produced. There were always some poor quality productions but there are just many more of them today. I also think that novels, scripts, and screen plays have become dying art forms.
Prose fiction is becoming harder and harder to market to men. I guess lots of men see reading fiction as unmanly or pointless. 'Why would read something that's not true!' It's going back to the reputation the initial English novels had in the 18th century. Only Oprah can help! /sarcasm