> Because property tax is an awful, dreadful way to fund public education.
I don't think the property tax is the issue. It's doing school funding at a sufficiently granular level that's the real issue—poor cities / districts won't have the same sort of tax base, be it collected via income, property, excise, sales, or somehow else, as do rich districts.
What you want is some sort of redistributive system. Really large districts (like entire states or countries) accomplish this as rich areas within the district subsidize less wealthy ones. Grants from higher levels of government, paid for by taxpayers in other parts of the jurisdiction, also accomplish this.
That said, money isn't everything...San Francisco has a tremendously wealthy tax base and an unusually small student population due to the city's demographics, but the schools aren't anything to write home about.
Property tax is progressive because rich people purchase more property, and real property tax is critically important because real estate is a permanently finite resource.
Progressive taxes are not linear, they are at least quadratic. The way many property taxes are set up now in the states, they are flat taxes by zoning - ie, residential pays a fixed rate.
I would absolutely argue for progressive property taxes, and that you either need steep progressive property taxes or homesteading rights to avoid the current bubble of land hoarding by the rich, but we don't have those now, and they should fund other things (and at a much less granular scale) than public education.
Highly dense young-urban-professional work-centric neighborhoods low on kids (SF, LA, SJ) would receive more money, suburban, rural and single-industry neighborhoods (towns in San Bernardino, Fresno counties) dominated by families with children would receive less money.
A progressive percentage of earned income above given thresholds (either poverty or happiness) would make much, much more sense.