The answer is that he could still afford to live there just no longer as an owner of that much land. In a city with a land value tax the rental or condo market would be much more dynamic so he would be able to find and affordable option their.
In the end the OP has a point. And even if this point alone is certainly not major and would ve a reason to drop the concept of a land tax, it's also relevant enough to warrant a serious discussion about it imho.