Mars is difficult of course, but it does have resources. You can get water, oxygen, rocket fuel, various ores, etc. It's also not a vacuum, and there are plac

Mars is difficult of course, but it does have resources. You can get water, oxygen, rocket fuel, various ores, etc. It's also not a vacuum, and there are places where the temperature profile is vaguely similar to Earth. None of that is true in space, unless you're thinking of something I'm not, but like another poster has said, none of this is zero sum. The technology developed to try to settle on mars can be devoted to building large, habitable objects in space if people think that's a better plan. We should also have a moon base, etc. etc.