The land value tax incentivizes the owner of scarce, valuable urban land to put it to good social use, such as building apartments for hundreds of people to live in. You would have to be astronomically wealthy to own two acres in a dense city and keep it solely for your own enjoyment. If you want two acres all to yourself, you can move to the countryside, where land is cheap, and one person can conceivably pay the property taxes on an engineer's salary.