The issue in most of the professional sports is a image issue both good and bad. The NBA actually did a good job of fixing its image issues from a few years back but like the NFL a lot of the high profile players for whatever reason are running into issues with the law, which reflects badly on the teams and thereby the NBA.
Sports in general are loosing viewers and thereby money, NASCAR which at one point was the fast growing from of sports has stalled. I think the issue is overload plus the explosion of the internet, cable and satellite tv services and of course the dvr (commonly called tivo's) which all have hurt sports and tv in general but like the music industry I think if they would stop trying to force feed us programs etc and let folks pick what they like more I think they would see better return on their investment and that holds true to for pro sports as well. I know that the NFL, NBA and MLB all have their own channels plus you have espn etc that reply the living crap out stuff to the point nobody cares not to mention every news channel has a sports segment that shows highlights etc to death the viewer and thereby fan becomes overloaded and stops caring