From a sociological point of view, it's not hurting anyone, it doesn't hurt the society, there's absolutely no real argument to say it's a birth defect.

From a more "natural" point of view, I guess I could see why you say that. But then again, homosexuality isn't something limited to human specie. You can observe homosexuality in so many wild species, I'm not exactly convince there's no "evolutionnary" reason for this to happend. And since we're still expanding, it's pointless.

From an even more global point of view, if homosexuality is suppose to be a birth defect because it tends to lower down the natality from an evolution point of view, it becomes a good thing. The earth is not meant to host 200 billions of humans, 7 billions is more than enough to fuck up the planet. We're responsible for massive extinction of species, destruction of so many ecosystem... Let's face it, if earth was a human body, we would be no better than a virus.

So, yeah. I could understand that someone tells me being gay is a birth defect. Then again, he would need to precise the point of view he's using here.

Once he tells me about the point of view he's using, I still need to hear what kind of point he is trying to get across using a pointless view, since birth rates are definitely one of the last threat for humanity (and there's a long list).

Maybe when we will have bombed our environment with so many chemicals than we become unable to reproduce (which is actually becoming not just "children of men" movie plot, but something actually happening), then we will start talking about the fact that homosexuality can become a threat.

But even then, I'm still not convinced that human extinction wouldn't be one of the best thing for this planet.

So, long story short, while I can kind of agree in some specific point of view with that statement, I'm really curious to hear about what more that somebody has to say further in a conversation. At this point I'd be like "All right. Let's agree on that if that makes you feel better about yourself. Then what, bring it on. What do you have to say about this supposed "birth defect" ?".

That's some kind of retarded statement with absolutely no deep thinking leading to no point. Congratulation to the idiot who brought this up.