Here's the issue: http://crossedgenres.com/blog/sff-market-rejects-our-lgbtq-ad/
It's a bit long, but here's the meat of it: The key element of true marriage is procreative sex. These are essentially linked. Therefore same-sex marriage is wrong, as is procreative sex outside of marriage. Contraception is wrong for married couples, as the purpose of marriage is baby-making.
I do wonder whether Mr. Frievald has taken this argument to its logical conclusion - that sterile men and women, women who have reached menopause, and anyone else who through accident of genetics or misfortune cannot or should not engage in procreative sex should be prohibited from marriage.