Same sex couples are not prevented from forming same sex 'families' by lack of access to state recognized same-sex marriage. They have every right available to heterosexual married families available through court filings except the ability to join together to procreate a 'family.' No court action can make their individual biology function to procreate together. They want same-sex marriage, not to strengthen same-sex families, but to get state sanctioning of the normalization of homosexual behavior.
There are many heterosexual families that are plenty strong without the benefit of marriage. These families are very common in the celebrities circle.
Research shows that heterosexual families produce children who are ahead of same sex chldrn