Bigotry is based on prejudice and stereotypes; hasty generalizations about a particular group (e.g. assuming black people are criminals). Insults may or may not be. Calling someone "f---ing Mormon" doesn't actually say ANYTHING about you, other than accuse you of being a member of a particular religion, and that said person doesn't like said religion. Under YOUR definition of bigotry, no one should EVER be criticized for anything. Its basically the fallacy of composition. All bigotry is insulting, but NOT all insults constitute bigotry.

The big reasons that racial bigotry and religious criticism are NOT equal is A) people choose their religion. They do NOT choose their race and B) being a member of a particular race does NOT actually say anything about said person's personal beliefs, values, customs, etc while being an active member of a particular religion speaks VOLUMES on such matters.