Let's presuppose that moving is not an option ...

People whose kids are forced to attend crappy schools, based on where they live, have a choice to make.
(Notice that word "choice" keeps popping up?) 

The free options are posted a few entries back. This avenue isn't free. The cost is skipping one or two iterations of the latest overpriced, sweatshop-made, athlete-endorsed gym-shoe that will be "out of style" in 6 months, anyway.
Oy vey, the sacrifice! The sacrifice!

Path 1) Parents can complain (ineffectively) about their school system, while letting their kids grow up to be idgits, thugs, parasites, and single parents with umpteen mismatched kids.

 --OR--

Path 2) Parents can get involved and add supplemental materials (e.g. Homeschool Curriculum) to the mix. *

* Yes, your kids may think you're an overbearing jerk, giving them "extra work, for no good reason"... until years later, when they see what their peers have become (see path #1) or as soon as they get their ACT/SAT scores and/or acceptance letter back from the school or internship of their choice.  Later, they can provide their own kids with better lives, schools, options.

Now, you gonna start making progress or keep making excuses?