How is it a weapon against your freedom - unless that’s the freedom to be a bigot. Same thing as enfranchising women, then black and first nations peoples, or allowing mixed race marriages. They don’t call it marriage equality for nothing.
Also, you neglect to mention all the homosexuals who DID support heterosexual marriages: cakebakers, photographers, florists, the bride’s hairdresser or even a gay wedding singer - yet could not legally marry THEIR partner.
Finally, you don’t need to be married to have children, or not, and this is hardly a virtue when there are 7 billion people in the world - why should we continue to breed like a mouse plague?!