As an alternative reason or explanation for why taxing "land" instead of property built on the land:
The idea is to tax based on the //potential// value of the area to society, so that realizing that value to society is incentivezed. I suspect a real application of this would examine the difference in value to society and apply more 'incentive' (tax proportionally more of the missing value) the further from actual value to society a piece of land is.
How does this not end with all existent small owners being strong-armed into selling out to capital-heavy investors who can afford to build 20-story towers? Or is the point that it explicitly does not protect them, because they are "under-utilizing" the property?
I'd expect that such a policy would result in a lot of cultural churn, and homogenizing of communities to the point of losing any sort of interesting historical character. How can you have history, when everything is being bought up and redeveloped every (x) years because the previous owners can no longer afford the taxes on the "improved value". Everyone becomes the victims of everyone's success.
When "historical charachter" and entrenched interests are making cities en masse completely unlivable for anybody but the top margin of society, we have a serious problem that needs solutions. "historical charachter" is a pretty shitty reason that people should go homeless
I'm confused why you put scare quotes around "historical character" -- it's a real phenomenon and a real concern. There are places where historical character is what drives the demand so high to start with. Sure, you could fit more people into the historical district... If you knocked down all the historical construction and basically removed all charm that's attracting people there in the first place. And one could always invoke tourism into this argument also. Those same districts also tend to be the ones that tourists want to see, precisely because it's different from what they know.
because its often a canard in many areas for "no new development so we can artifically maintain a shortage, and keep our property values sky high".
Sorry but your property values and neighbourhood appearance shouldnt be winning out against people literally being unable to live inside cities because they have comitted the crime of being too poor.