This is an excellent and important point. If your ambitions lie along the lines of "supercomputing, nanotech, quantum computing, Internet-scale problems," etc, then skipping college is a terrible mistake, obviously.
It comes down to what he wants. Personally, I wanted freedom from debt, freedom from high school, and the freedom to work with creative people. Those factors made me decide to drop out of high school (after I had landed a game development internship, i.e. a solid job and therefore a solid resume for the future).
I think it's important to not seem like you're looking down on people who DO chose to go to college. Because surely you wouldn't like it if they looked down upon you?
Truth is you do get a lot more from college for your debt load than just job training.
(And just so you know, I went, but didn't finish, largely because I found myself making a very good living developing software and also because my personality has never accommodated being part of the student-underclass.)
It comes down to what he wants. Personally, I wanted freedom from debt, freedom from high school, and the freedom to work with creative people. Those factors made me decide to drop out of high school (after I had landed a game development internship, i.e. a solid job and therefore a solid resume for the future).