Do you know people who work or have worked for him? I work in the clean tech industry and know several people who work(ed) for solar city or Tesla. Musk is, I hear, a great recruiter, but then overworks his talent and eventually they burn out.
As for the mission - seems mostly legit though I don't think Elon is motivated by climate change otherwise he wouldn't be using Natural Gas for fueling his rockets more for ability to create self sustaining energy off planet.