To the extent that minorities are more likely to be of lower socioeconomic status, and that society largely self-sorts itself into neighborhoods based on socioeconomic status, and that public schools are largely funded locally in the US, and that lower funding in more needy schools leads to poorer outcomes, then, yes, maybe...
A bigger problem is that my students in a (violent) big city come to school less often (high absentee rates), come to school tired (less parental oversight to enforce bedtimes), come to school preoccupied with parents being in jail, come to school with less parental involvement in the education process and parents who sometimes don't care about grades at all, come to school and fight or throw gang signs or do other violent activities that undermine the educational environment.
None of these things I can change. We call this being " unavailable for learning."
What I could do was move out of that area and into a nice suburban area and send my child to a school with children who are rarely absent, have parents that enforce bedtimes so students are alert, parents who volunteer in the classrooms, care about grades and make sure their kids are not out on the streets joining gangs, and are most assuredly not in jail. Unsurprisingly, these schools have a better educational environment and higher achievement.
People self-segregate by socioeconomic status. People tend to live in the nicest neighborhood that they can afford. Public schools are community schools, so they reflect the surrounding community. In fact, great public schools can increase real estate values, self-reinforcing the trend.
What I wish people knew about teaching is that teachers in good schools work half as hard as teachers in poor schools. I work 10 hour days to try to make up for the conditions I described at the outset. Some students I connect with and they are success stories. I feel good that I've made a difference. But, I can't follow students home, make them do their homework, put them in bed at a reasonable hour and make sure they stay off the streets. I only have these students for 6 hours out of 24. It's no surprise, then, that their achievement is lower! It's frustrating to work twice as hard for lesser results, and this is, in fact, why there is such turnover, especially in lower-performing schools. My district micromanages the exact lessons that teachers use, almost down to the words to say. Achievement is fine with those lessons in relatively prosperous schools, but in poor "bad" schools, those same lessons do not produce the same results. Surprise! It's not the lessons!