Jesus proposes it as the basis of his two great commandments, which fulfill all the law and the prophets. There is ample proof of these facts in single parent families. While many people in "average" marriages care for kids and each other well, LGBT's often do it better. His email address is ldickie seattletimes. But on several occasions I have heard people argue that because some heterosexual couples are unable to procreate, procreation itself provides no rational basis to support heterosexual marriage and not SSM. Universal values are certainly not always the same as traditional family values.
I discard tolerance as I do not want to be tolerated for my dignity, but accepted and celebrated for it.
In recent years, legislators have revised state laws to provide the statutory equivalent of marriage. Gays and lesbians seek the civic and social recognition that fully creates a family in our culture. The conflicting desires of fitting in with family and fitting in with friends could cause them stress and confusion over what their preference really is. It does not totally rule out interest in, care for, and attraction toward members of the opposite sex.
All of which allow you to argue against marriage, which is why so many people see the divorce from context as an attack on marriage.