Gates and Broad and whoever else controls education reform direction have an assumption in common. Namely that poverty doesn't matter. To prove this, they point to KIPP schools where great test scores are achieved. More on that in a minute. I don't know much about what else they accomplish at KIPP schools. I have a vague notion that they excel in performance arts as well, which is great. Anytime a child gets arts experience in school, it's a good thing.
I have a few major problems with this, mostly that students are selected to go to KIPP (self-selection counts) and that all they demonstrate with high test scores is success on tests. It could just be gaps in my knowledge about how much success kids have in KIPP. But the self-selection and ability of KIPP schools to dismiss students both undermine the idea's scalability.
Until we address America's 23%-and-climbing rate of child poverty, the scores posted by poor students are going to continue to drag the average down. I don't mean to be cruel here, but scores by non-poor students are generally fine. In some cases, better than many countries'. Poor kids need some basic needs met that are traditionally not the responsibility of schools. You're familiar with Maslow's hierarchy of needs I hope. Throwing more money at the administrators or putting in bonus programs for schools (as in NYC) will not accomplish this. There was a guy in Harlem with a charter I think who put in a dental office in the next building over because his students were not getting dental care. That's a start.
School reform efforts that ignore or dismiss concerns about poverty will always fail.
Note that this is still better than the conservative vision of school reform, where the greatest resources are spent on the highest (student) achievers and everyone else gets enough education to serve as their working class.