Attendance and ratings were down in 2012.
http://aol.sportingnews.com/nascar/story/2012-11-21/nascar-tv-ratings-decline-fox-espn-tnt-daytona-500-olympics

You would think that if attendance was down that ratings would go up a bit but that hasn't happened.
NASCAR's attempted innovations, like the "Car of Tomorrow" (a boxier car meant for safer, closer competition used from 2007-12) and the Chase for the Cup (making a points system that only allowed the top 12 in the standings to win the championship even though races still feature 43 cars) have pushed away a chunk of the hardcore crowd.

Hell, some people probably miss when they called it the Winston Cup. Certainly they don't like this little no-winning hussy Patrick being shoved down their throats as a new star. Especially when they've got two developmental leagues full of drivers trying to push into the big time.