Historian
I've never seen convincing evidence that groups' values or their cultural beliefs are the sole causes or primary causes of these discrepancies. Consider some of the most often cited causes for black or Hispanic poverty. You mentioned some: lack of investment in education, poor parenting, excessive substance abuse, domestic abuse, criminality, inability to save money. This might be a persuasive argument if, for example, the rates of substance abuse or domestic violence were statistically ...
Sociologist
I would just say that this argument puts the cart before the horse. If you change the social structure, the economic opportunities - within one generation, rates of success will be more equal. We can debate whether there are different values and whether those matter or not. But really, these differences are often the effect, not the cause.