Federal, state and local governments need revenue in order to operate, and the military, education and Social Security need funding to work. But property taxes are an unreliable and inconsistent means of raising that revenue. Property values, as we've recently experienced, are not stable, and when property values fall so does revenue, at a time when revenue needs to be stable. It can make a recession worse than it has to be.
I think almost all taxes should be based on consumption (sales taxes) and income. This would stabilize budgets and help us recover from recessions like this more quickly.