I think what happened was that a lotta people were shocked when AP declared he would be playing that Sunday. I'm sure a lotta people, including myself, were thinking he should be with his kid. Then when the story came out that he had only known about the child for the last 2 or 3 months. Well, the gloves came off so to speak.
That, and it came to light that he had never even met the kid until after he was on life support. Adrian Peterson was about as close to that child as I was. I don't necessarily hold him accountable for that, because like you said, the child's paternity until recently was clouded.