From the Spacefuture.com site.

An interesting analogy, but with a couple of holes. I dare say that if the Moon had been a bit larger, and had an oxygen atmosphere, plants, and water, that we would be trying one hell of a lot harder to get there than we are. I also think that if the western half of the United States actually HAD been comprised of middle-Sahara type dune desert all the way to the Pacific, the "great American movement westward" would have been not so great.

Now, if the equivalent of California gold can be found on the Moon,* we might have something.

*And no, it's not Helium 3. We can't even burn tritium in fusion reactors yet, and that's a lot easier.