Historically speaking "gay" wasn't even an issue, or even a particular distinction, for several millennia. Even the modern religions didn't start going after gays until only fairly recently in terms of the span of human history.
Also, when you look at someone, you don't automatically think "gay or straight" (unless of course you have gaydar...) but I bet you do see black as black and for a lot of people have a reaction, even involuntarily, due to so much negative stereotyping in our culture towards blacks. Even anti-gay people don't look at a gay person and think they are going to be robbed, raped, and murdered the way so many people, even those that on the surface of things would never admit to being race phobic, do when they see a black person.
I am not saying gays haven't been unjustly persecuted at all. The Nazis killed the pornographers and the gays before they got around to the Jews, for example. Gays have been lynched and murdered across the globe so I definitely am not saying that they haven't had their fair share of civil rights abuses on which to base the context of the statements that sparked your neighbor's reaction.
Think about it this way... a gay person is free to choose to hide their sexuality but a black person is always going to be a slave to their skin color, so in terms of persecution, any kind of discrimination or hate, one group can choose to avoid it while the other cannot.
You know, the ironic thing, all of what I am saying and the point I am trying to make, was imparted to me by a gay black man.
