Some people are tying to fit it into the argument, not using natural relatively but generally for all people. These people need to define natural in this debate. Some have tried but those calling homosexual unnatural fled the debate declaring it semantics. Well, if they insist on using a specific word to describe something, and other people disagree on what that word means, they're gonna have to get into semantics.
RCS refuses to have this discussion. He wants to declare homosexuality unnatural and will only tolerate a certain level of criticism. If you read the thread, the kind of criticism he'll accept is clear. He only wants people to discuss an implied moral argument or homophobia in his arguments, so he can deny it and be a victim of unfair accusations. Even when people didn't make such implications, he still insisted on satisfying that persecution complex. Better criticism of his position caused him to leave.
He stated his beliefs clearly - You disagree - that is fine - He made his points and saw no further reason for discussion. Again nothing wrong with that.