The biggest justification for that was this very issue in the article. But boy, didn't American media kept downplaying those abuses and incidents pointed by the Russians... And kept insisting that it was a retaliation for the Magnitsky act. IMHO the ban indeed was a retaliative act, but these problems presented by Russians at the time could have been at least looked at. May be then the existence of the issue would be recognized, accepted and trigger some further protective laws for the adopted children. I didn't see one single major American news outlet who touched on this part, all simply ignored it as a mere 'yet another poke from the Russians'.
Most of the developed countries forbid adoptions of country nationals by foreign citizens, how many US children got adopted by foreign countries?...not sure why Russian media is making such a big buzz around this law, probably just to find one more way to criticize Putin.
Honestly I am not sure whether the Russian media made any big deal at all out of that, I would bet in fact even if they did, it was far (lower) from the extent to which American media did. Not to mention the protests held by thousands in the US.
