> A nuclear holocaust would not kill all the humans. A major asteroid strike would not kill all the humans. A super-flu pandemic would not kill all the humans. A single short circuit, puncture, or virus could kill all the humans on Mars.
Terraforming Mars would prevent a 'puncture' or 'short circuit' from wiping out its population. The goal isn't to only spread human life but all of life.
You don't? That assumption is extremely obvious to me. Most people don't care about Mars right now - in fact, most Americans are against space travel because they think it's expensive. So, terraforming Mars is seen by people (including those with money) as ridiculous. But if SpaceX puts a team on Mars for less money than, say, making a blockbuster film, an obvious result is massive increase in space travel, colonization, etc.
Progress is progress. Choosing to make progress accelerates the process, especially when the progress we're talking about would be the first humans on another planet (and the first known life on Mars).
Terraforming Mars would prevent a 'puncture' or 'short circuit' from wiping out its population. The goal isn't to only spread human life but all of life.