Are you seriously saying sanctioned acceptance of ssm is going to lead to more people lying to their kids about who the biological parents are?
My family tree on one side has 2 adoptions, and one into state care, and mostly because way back in the conservative 50s: nobody spoke about kids out of wedlock, they were often adopted out or taken away or sent away - those children were a problem. Let alone disabled children. A heinous state of affairs - and one largely driven by the church and moral police.
Acceptance and tolerance is the answer. Not more discrimination.