Local school funding

Why are public schools in the US primarily funded by local property taxes?  It is hard to think of a clearer example of class discrimination in this country.  People with higher educations tend to have higher incomes and can live in areas where property is more expensive, which means the local schools are better funded so that their children have better educations and the process continues to repeat.  Lower income people can only afford areas with lower property values and less well funded public schools for their children.  The US system works to separate people by class and strongly reenforces this generation after generation.  Why do we allow this?

I have seen arguments that it is « unfair » for richer school districts to spend more on poorer school districts, but the poorer ones don't have the money to spend in the first place.  It is not like they are cheating the system and keeping extra money somehow.  Also, we are talking about children's education here; a part of the population that has no say in how the system is set up and is not allowed to make these choices that are critically important to the rest of their lives. 

It is like the argument that retired people should not pay taxes for schools because their children are not in school.  Does anyone ask people that are still working and do not have children if they would like to not pay taxes⸮  Should people pay more taxes for each child they have⸮  Of course not.  It is better for everyone if we all live up to our fullest potential.  Do retired people not care about their grand-children's generation⸮  When retired people have medical issues and go to the hospital they want the personnel to have a good education, but some are trying to get out of paying for it.  Similarly, people in rich areas complain about crime in poorer areas, but they want to keep their public education taxes local and reenforce the negative cycle in poorer districts. 

Being limited in education and thus job opportunities from generation to generation is like creating a caste system.  Funding for public schools needs to be disconnected from local taxes.  Is there any reasonable argument to the contrary?