This word can also be a weapon, such as when moral relativists use it to suggest that anyone who isn't a moral relativist is a bigot. And you can almost see moral relativism in the definition. Reading it, I can imagine times when being a bigot would be a good thing.

It's difficult to use this word fairly or in a way that doesn't make the user a bigot by the definition in some cases. Plus, unreasonable is subjective. It's a vague term that gets used too loosely too often, but the definition is largely to blame for that.