"My guess is that..."

Would you be able to provide some of the evidence that led you to this guess? Or maybe you could give us your credentials, whatever education and experience you have that qualifies you to make guesses in the field of pre-Columbian Neolithic archaeology?

Let me make it simpler: How do YOU know that 2-year-old death was "common" among these people, at this time? What supporting sources to this putative fact?

I can understand being skeptical of the article author's conclusion, if they did a poor job explaining themselves... But your counter-hypothesis is just creative writing, without something a little more solid to back it up.