Oh, it's a far worse problem than having the property tax base to create the district, but avoiding the students that would need extra support, and might disrupt the classroom because they aren't getting it. Those students are incredibly expensive to handle mainly via the school district alone. The amount of money to provide sufficient support without parental involvement is beyond what even the wealthiest districts can afford. The shortcut to avoid said students isn't to have immense funding then, but to make sure parents that aren't rather wealthy don't even get into live in the district a all.

That's the real dirty problem of the suburb + school district marriage: You turn parents just thinking of the school district of their children into raging NIMBYs that end up wanting just rich people that speak perfect english nearby.