Philadelphia Eagles fans have two main emotions. The most common one is irascible doom-mongering. “The team sucks”; “I loved the guy they got rid of”; “that was the stupidest decision ever.” As Brandon Lee Gowton of Bleeding Green Nation puts it: Some people are not happy unless they’re not happy. #makesuthink — Brandon Lee Gowton (@BrandonGowton) August 8, 2014 Chip …