I think in some (most?) countries you get "special" rights when you are married. Most of those rights are based on the thought you will stay together, share apartment/house and most likely become parents I think. That last thing is a no in gay marriage. You can adopt children but you are not "making new ones".
But yeah, most people are just against it because of religion (but still don't care about weapons, for example...) or because it's "different".
Let people do whatever they want. But if there are special rights for "normal" marriages, kick those out of the rights of gay marriages, maybe create different ones. They will still cry not being totally equal but hey ....







