And that is why they are losing.
Family is based on DUTY, loyalty, reciprocal obligations, and blood.
If it's not, it's nothing, which is where we are headed at lightning speed - not least because of idiotic remarks like "we believe family is based on love".
I quite agree.
Love grows after a marriage, after a lifetime of sharing responsibility & cultural values. This doesn't mean, however, that chemistry isn't important. There must be some kind of attraction & compatibility, some commonality of background, goals, etc. However, love is not the focus. As you said, it's duty & loyalty.
Gay marriage is the proof that the concept of "love" in Western society has become a farce. It is just as easy to fall out of love, which usually results in a union based totally on sex or emotions. This is the reason most gay marriages fail -- as well as many religious or ethnic "intermarriages," even among heterosexuals. There is no foundation. People who throw away tradition really just want to do their own thing. Instead of accepting the reality of marriage, they are basically shooting the arrow, then drawing the circle around it.
Two people doing their own thing are just two ships passing through the night. Tradition has a way of biting back.