Read the article, though. This is stunning, but plenty just as stunning:
Samples did not include heterosexual comparison groups. Marks finds that "many same-sex parenting researchers did not use marriage-based, intact families as heterosexual representatives, but instead used single mothers." That is to say, outcomes for married, intact mom-dad families were not the basis for comparison in the research studies to the same-sex parents; instead, same-sex and single-mother households were compared.
Question: If you cheat right out in the open, can you pretend it's not-cheating?