Moon colonies are fools good. We should go straight to Mars, and there's a decent chance we will in the next 10 years. The question is will it be done haphazardly with no governmental oversight by corporations, or in a orderly fair manner by NASA and its foreign equivalents.
Mars has long been uninhabitable, and that's a fact. Was inhabitable maybe millions, billions of years ago? Yes, but since then it's simply not going to work.
Well yes, it's going to take pressurized domes unless we manage to terraform it one day (which would take centuries), but that's doable.