I guess I'm too young to see how gay marriage is even controversial, but where's the frontier between bigotry and discrepant values?

Is being anti-abortion bigotry & hate?

For gay marriage, the part that made being against it bigotry is the part where you are denying other people fundamental rights, and all of the ancillary rights that go with that. You are, in essence, creating second class citizens. And for something that literally had zero effect whatsoever on those that were against it.

There are people who genuinely disagree with you and believe that same-sex marriage is not a fundamental right but a separate additional right requested by the LGBT community.