Actually, the definition is generally given as something like :"One who is strongly partial to one's own group, religion, race, or politics and is intolerant of those who differ."
That's a lot closer to the gay guy's definition than to that of the author.
That definition is wrong: a product of modern revisionism.
Bigot means ‘a narrow-minded, prejudiced person’. It is therefore redolent of prejudice: which means judging ‘before’ the facts.