That sounds like a really, really good idea because it would shift tax burden from people that have done socially positive things in a city context like adding

That sounds like a really, really good idea because it would shift tax burden from people that have done socially positive things in a city context like adding population density building multiresidential and shift it to people leaving dead zones of low density decrepit garbage. On the theory of making things you don't want cost more and incentivizing things you do want my making them cost less, that's a great idea. My only concern would be rezoning land into a higher tax bracket causing distress to the original owner, which they could do by grandfathering zoning for tax purposes until a property is sold.