If "Chairface" (it says something about me that I didn't have to look that up) has a laser cannon that can write on the Moon, I'm not going to argue with him.

If a more real-world trillionaire decides to throw enough infrastructure into space and onto the lunar surface to be able to mark the Moon visibly using real-world construction techniques--well, that's a tough one.

That kind of infrastructure is enough to do serious mining, colonization, and exploration of the Moon and asteroids in their spare time. Louse up the face of the Moon in return for getting humans into space in a big way?

Well, hell, we can always restore it again after the old coot croaks.