As bad as the Pirates are they drew 2,091.918 fans for an average of 26,148 pergame. In 2010 (i left out 2011 because of the short season) the lakers drew 778,887 for an average of 18,997 per game. Los Angeles and their market is a lot bigger than Pittsburgh, but its basketball, and as much as you may not like it basketball still trails baseball in popularity.
Basketball arenas are A LOT smaller - horrible comparison. Look at TV ratings and basketball is on par with baseball. Some years the NBA Finals outdraw the World Series and vice versa. For example:
2010 - NBA averaged 10.6 ratings and 18.1 million viewers while the MLB WS averaged 10.06 ratings and 17 million viewers.
2011 - NBA averaged 10.2 ratings and 17.3 million viewers while the MLB WS averaged 11.3 ratings and 18.9 million viewers.
Sources - http://en.wikipedia....evision_ratings