I think that you may be missing the point of the argument that you are replying to. As I understand it, what they are getting at is that no one created the land, it was already here. Therefore, it's not valid to say that the person who originally claimed the land had a right to it in the same sense that, for example, a farmer has a right to what they grow because of the labor they put into growing it.

In effect, the argument is that since land was not created by anyone then no one has any more right to it than anyone else. So the land's value should be shared among all of society; which is precisely what a Land Value Tax seeks to do.