Two Points on Homosexuality and Gay Marriage

In discussions about Homosexuality and Gay Marriage, two things always edge their way into the conversation. I'd like to discuss those two things with you here.

1. Homosexuality is "Unnatural"

and

2. Gay couples don't contribute to society the way Heterosexual couples do (that is, by procreating).

The first, that Homosexuality is unnatural, is used merely to show why Homosexuality is "wrong". But what makes Homosexuality wrong, and what makes it unnatural? By whose standard are we holding Homosexuality?

Recent studies have given us much insight into the fact that Homosexuality is more genetic than anything else. That said, if in fact Homosexuality is genetic, it could not be considered any more unnatural than a Heterosexual man or woman being sterile.

That last statement ties in with the second point that "Gay couples don't contribute to society the way Heterosexual couples do". We allow civil marriage to all Heterosexual couples, regardless of age and fertility; yet we deny the same type of civil marriage to Homosexual couples. Why? Because they don't all procreate? Why then do we allow sterile Heterosexual couples and elderly couples to marry? After all, they can no longer provide that same contribution to society. What gives them any more rights than anyone else?

Thoughts?