Land Value Tax

This isn’t really apropos of anything, but is there any reason at all to think it makes sense to tax property values rather than land? I wasted an hour or so this morning googling and reading about the idea of a land-value tax and the case for it seems (a) extremely compelling and (b) to be made primarily by cranks. So what gives here? How come the economists of America aren’t uniting in insistence that we make the switch?

To lay the case out simply, the problem with taxes from the standpoint of economic efficiency is that they reduce the incentives to do stuff. If you tax wages, that reduces your incentive to do useful work. If you tax property values, that reduces your incentive to invest in valuable structures. But the land area of jurisdictions is more or less fixed. Obviously there are some exceptions but in general the land area of the United States of America is not subject to change. So there’s no productive activity to disincentivize. Sounds awesome. But instead of being in place throughout the country, we use this system in just a few parts of Pennsylvania.