Pirates fans are not loyal. Not quite as disloyal as Royal Fan fans, but very disloyal none the less.
The Brand Keys Sports Loyalty Index was released for 2013, giving the five most loyal and least loyal fanbases in baseball. The Phillies ranked second on the list, behind only fans of the New York Yankees. The rest of the top five includes fans of the San Francisco Giants, the St. Louis Cardinals, and the Atlanta Braves.
The bottom five in baseball are fans the New York Mets, Seattle Mariners, Pittsburgh Pirates, Kansas City Royals and Houston Astros.