Elon Musk is preparing to colonize or terraform Mars in the future because he believes that it is important for humanity to become a multi-planetary species. He has stated that he sees this as a way to ensure the long-term survival of humanity and to reduce the risk of extinction events.
Musk has argued that Earth is vulnerable to natural disasters, such as asteroid impacts or super-volcanic eruptions, as well as human-made disasters, such as nuclear war or catastrophic climate change. By establishing a human colony on Mars, he believes that we can create a backup location for humanity in case of such events.
Additionally, Musk has argued that the development of Mars could lead to advances in technology and innovation that could benefit humanity more broadly. He has stated that the challenges of colonizing Mars would require new technologies and approaches that could be applied to a range of other problems on Earth.
Finally, Musk has also expressed his belief that the colonization of Mars would be an exciting and inspiring endeavor that could help to inspire a new generation of scientists and engineers. He has argued that this could help to drive progress and innovation in a range of fields and ultimately benefit humanity as a whole.