Land is a natural resource

If a Bond-style villain sucked all the oxygen out of the atmosphere, and people had to buy containers of oxygen from his organisation or suffocate, most people would instinctively accept that this is wrong - only a few unscrupulous people would applaud his business acumen.

The maximum price that he can charge is unaffected by the costs of extracting and bottling oxygen, he would set it at whatever people are willing to pay, which is pretty much the whole of their income - as the alternative would be to starve to death.

Why is it any different if there were just one or many such Bond-style villains who between them control the whole world's oxygen supply?

And why is it any different if a minority of companies or families declare themselves to be owners of the entire earth's land surface?