Homesexual Marriage Being Illegal or/and Anti-Religious

Sparked from a status message from my wife, people are quite unsure as to why homosexual Marriage is illegal here in the U.S.  Pretty much everyone agrees the only reason is due to (Christian) religion.  I disagree, though it may have some subconscious influence.  I think the reasons are thus:

1)  Procreation.  Homosexual couples cannot have children without a heterosexual relationship and we sure needed our population to grow when the country first started (just like now, the government doesn't really count natives) to production up and to start up our economy, not to mention keep those going and expanding over time.  We also needed personnel to fight against our various motherlands as well as the natives.

2) A range of discomfort to fear.  For this, I should say, of being approached in hopes of starting a homosexual relationship, especially in a very forward manner.  Most heterosexuals that are propositioned by those of the same gender are very uncomfortable when propositioned or, when around homosexuals, fear being propositioned.

3) Fear of the self.  I can't say, first hand, about women, but I know most men, when they are first discovering themselves, fear they are homosexual and for a bunch, that fear never goes away (which is why calling someone gay, a fag, a homo, et al) is reacted so strongly to when used as an insult.  The reasons for this fear is rooted in religion, though that isn't, shall we say, the (obvious) reason given.  The reasons are the taboo of homosexuality, the fear on non conforming to what is the norm (heterosexuality), and social conditioning (from society, from parents, from friends, from T.V and many others I am sure).  Unfortunately, all of those religions stem from religion.  I'm sure some will say no, that our evolution created sense of procreation is also a reason, but I find that to be dubious as there is evidence of homosexuality in most animals as well as the beginning of written/drawn history.

More reasons will probably come up, though as I have shown, religion isn't the only reason for homosexual marriage being disallowed.