kids with a poor home life often act out in class, or have other behavioral issues. It’s not their fault, and it’s not “fair”, but it IS a valid characterization.

I don’t think it’s controversial to say that kids with a great home life _probably_ have parents or grandparents that advocate for them and really try to get them placed into a good school district.

One could argue that getting your child into a good school district is an indirect way of surrounding them with like-minded kids and parental influence.

True, but look to the generalization presented in the original comment, where an overall trend was suggested. What makes one district filled with "good" parents and kids, whereas another was "bad"? To say nothing of the implication that the commenter was one of the good ones in the land of the bad.

My premise is that there's underlying causes unmentioned, but implied (like socioeconomic status). You can separate groups from membership, and to oversimplify, if you move something from one side of an equation to the other, with different results, what you moved was truly the constant, and what was left behind was the variable.