Why not both?

I think it's both the incompetence of the incumbents, and the impressive work of SpaceX that got us to where we are. With the vast majority of companies, especially tech companies, I think the leadership gets far too much credit. In most organizations I have been a part of, they succeed in spite of the leadership, not because of it.

In the case of SpaceX though, I am less sure. Reading the Walter Isaacson biography on Elon Musk was quite fascinating and illuminating about his leadership style. I would never work for him myself, but he does have some really fascinating philosophies.