Property taxes go towards funding local services (schools, police, etc) whose costs tend to be proportional to the population size as well as the local cost of living. How else would you suggest funding these services?
Taxes also get levied when property sale makes you profit (capital gains tax). You also charge utility fees by location and service - a flat tax on such levied at the local level.
Why should someone who's property is worth more be forced to pay a higher tax for the local school, police, etc, when they don't consume more of those services?
Obviously that wouldn't be tolerable in contemporary America, but there is still something absurd about suggesting that because some houses in my neighborhood sold for more last year, that I should have to pay thousands of dollars more for the local government.
The massive inflation in city and state budgets due to soaring property taxes is a huge abuse of the middle class and transfer of wealth to the pork barrel of connected insiders profiting from government contracts, grants, etc.