Is there a reason why we can't just land somewhere?

Robert Zubrin has an article on NASA's Worst Plan Yet, the plan to build a space station in orbit around the Moon.

We do not need a lunar-orbiting station to go to the Moon. We do not need such a station to go to Mars. We do not need it to go to near-Earth asteroids. We do not need it to go anywhere. Nor can we accomplish anything in such a station that we cannot do in the Earth-orbiting International Space Station, except to expose human subjects to irradiation ... If the goal is to build a Moon base, it should be built on the surface of the Moon. That is where the science is, that is where the shielding material is, and that is where the resources to make propellant and other useful things are to be found. ... In contrast, there is nothing at all in lunar orbit: nothing to use, nothing to explore, nothing to do. ... Explaining his winning strategy for war with Austria, Napoleon Bonaparte once said, “If you want to take Vienna, take Vienna.” Well, if you want to go to the Moon, you should go to the Moon. You don’t go 99 percent of the way there and then hang out in orbit where you can do nothing.

I don't really know enough about this to justify having an opinion, but I have one nonetheless: I agree with Zubrin. As he says in that article, there was some hope that President Trump would push for a return to the Moon within four years, and landing on Mars within eight. I think we should set up permanently occupied stations in both places, rotating crews in and out whenever it's appropriate and feasible (for Mars it would have to be when it's in opposition with the Earth). Moreover, this would generate a great deal of industry and technological advancement, which would obviously involve a lot of job creation.

I recently watched this video that tours the Amundsen-Scott South Pole Station...



...and I thought, "Wouldn't it be awesome to have something that extensive on Mars?" I know it's not realistic. The reason spacecraft and space stations have so little ... well ... space inside is because you have to fill it with breathable air, which they have at the South Pole but don't in space or on Mars. You could probably have something that converts the much thinner Martian atmosphere into breathable air, but that would be a huge expense, and the less space inside that you need to fill with air, the cheaper it would be. But, man. Wouldn't it be awesome?