Interestingly, I agree with all these points of view, as they are all credible and contributing factors in the discussion.
Riddile is simply pointing out the role that poverty is currently playing in the achievement gap and its impact on international test scores. That seems pretty indisputable. And, of course, David Brooks has written continuously in the New York Times of brain research and the impact on children who do not form stable relationships by the age of 18 months. It can have a life-long debilitating effect. Of course, Brooks subsequently argues that because poverty is so debilitating and such a huge factor in the educational and career success of people, the institutions designed to combat those forces are all the more important. But Meyer is overstating his case by using the word "Myth." It's not a myth. Poverty does matter. Big time. It's not a myth that parenting, socioeconomic status, and neighborhood are the pinnacle of influences on a child's educational success. That's a foundational idea of reform efforts such as Geoffrey Canada's Harlem Children's Zone. That said, schools and teachers must not use it as an excuse. It's not why kids "can't" succeed. It's simply a key factor in why they don't.
Even Jaime Escalante couldn't reach all kids.