Science is an enterprise that should be cherished as an activity of the free human mind. Because it transforms who we are, how we live, and it gives us an understanding of our place in the universe.
Private enterprise in the history of civilization has never led large, expensive, dangerous projects with unknown risks. That has never happened because when you combine all these factors, you cannot create a capital market valuation of that activity.
Private enterprise can never lead a space frontier. It's not possible because a space frontier is expensive, it has unknown risks and it has unquantified risks.