Bolden was sharing his perspective on available technologies here. He wasn't discussing the economics of human deep space-flight and how those tie in with with NASA's mission as a public entity.

Sure, I'm astounded by SpaceX's technical prowess and aptitude to reduce the price of human spaceflight by magnitudes. There's no denying that.

I'm skeptical about their business model and the potential risks and second-order effects involved in handing a single party the keys of a multi-billion dollar, nation-state sized program to establish a human / U.S. presence on the moon / space. Because that's essentially what many proponents of commercial space flight are implying by directly pointing to Starship as the alternatives that (seemingly already) outclasses SLS.