Bigotry

Bigot is a pejorative term for a person who is obstinately devoted to their opinions, often engaging in a rude and intolerant manner when these are challenged. Forms of bigotry may have an related ideology, like racism and nationalism.

Bigotry is not "intolerance," but "unreasonable intolerance." Jews are understandably intolerant of Nazis; that doesn't necessarily make them anti-Nazi bigots.

An example from computing: A bigot may be a person who is religiously attached to some programming language, operating system, software or hardware product and often advocates it enthusiastically. A bigot will often refuse to find alternatives to these, even when technological advancements has been introduced since their release.

See also: zealot, partisan