There isn't a single cite in this entire thread to back that claim up outside of the anecdotal examples. The numbers for online ad sales and media revenue are all growing. The fact that the numbers haven't propagated through to Google's results is further proof of that.
Edit: some stats. The IAB report for last quarter shows 6% quarterly growth:
http://www.iab.net/about_the_iab/recent_press_releases/press...
Google ARPU for USA increased 7% last year:
http://www.statista.com/statistics/306570/google-annualized-...
Facebook ARPU is increasing 80% :
http://www.statista.com/statistics/234056/facebooks-average-...
Mobile ad growth up 83%:
http://www.wsj.com/articles/mobile-ad-spending-leaps-but-tra...
So where is this reported decline? It doesn't show up in numbers anywhere. There are profitable and well-run media businesses with both low and premium content in all sectors. I understand the tendency to want to blame this on some meta trend, but it just isn't there and can't be backed up outside of stories and feelings.