I think he's saying that if you can't do it in the desert then you shouldn't be talking about trying to do it in orbit. Work through the problems before you add in the launch costs and all of the other complications.

This is also what I say to people who propose a permanent Mars colony. They should be re-creating the Biosphere project right now and making it a success before the rocket is ready to go. There are a lot of problems that are seemingly still unaddressed with the whole project.