So many people have tried to change the public schools, and it just hasn't worked. Meanwhile their children suffer in the schools while the parents fight for change.
Public programs tend to be run badly.
I think that the only thing that might change public schools is if enough people leave the system, either to homeschool or by choosing private schools instead. If enough people do that they just maybe they will start to realize that they can't continue to be as terrible as they are because they are losing their 'customers.'