Elon musk cannot bear children so it doesn't matter how adventurous he is or isn't.
That's what it comes down to. Anyone who decides to colonize space with a permanent settlement isn't just making the decision for themselves. They're making it for their offspring too. Good luck finding mothers who would willingly do that to their children.
You won't have an increasing population because women do not willingly being children into inhospitable, terrible conditions. It's just not a choice mothers would make... ergo, the environment must be made more stable, viable, and pleasant to live in first than what a biodome or subterranean habitat could provide.
Again, I'm sure those things will.come first. But they won't be permanent human settlements where the population is intended to support and replenish itself. They'll be temporary and for specific purposes like mining.