[Spartacus]

There are married people who don't wish to have kids as well. And scientifically, there are ways homosexuals can get a child. IVF for one. The only non-religious argument that could be against homosexual's marriage is that it would definitely affect the roots of the system(be it housing/healthcare) that has been in placed for hetereosexuals for decades.

There could probably be other unforeseen negative circumstances that comes out of this. Btw Schlacko, there are some societies which still values the 'sanctity' of marriage.