Why do people say you are not "manly" if you dont follow football?

American football carries the same stereotypical connotations for American males. The ones who enjoy it don't understand why others don't and are less likely to accept it than females. Personally, I know men who don't follow and I don't think any less of their masculinity for it. You are who you are and it sounds like the people you're referring to are too superficial to accept that.