Respectfully I'm not seeing how your point is surprising at all. Are you just saying that when we do spend money on disadvantaged (whatever word is correct for "opposite of gifted") it isn't effective?

I'm just saying that when the institutional schooling system seems to "spend money on the disadvantaged" it's merely pretending to help the disadvantaged and marginalized, while actively rejecting the approaches that, at least as judged by readily available evidence, would likely help these students the most, and probably close at least some of the gap in outcomes.