cry havoc

It's no excuse, much less a real reason, but it's human nature to categorize, often to the point of the fallacy of Hasty Generalization. I don't like peabrained fundamentalists and televangelists, therefore Christianity is bad. She doesn't like man-hating Feminazis, so Feminists are bad. He got beat up by a Black kid in elementary school, so all African-Americans are N*****s. You don't like powermad warmongerers, so Conservatism is bad. And so on...