What I find interesting in your anecdote is the son chose to attend university and develop his talent as an athlete before starting full-time work as a plumber.
Even though the university experience might not have a monetary "return on investment", he chose to pursue it.
Now, it's also worth noting he's on scholarship. Whether that was the deciding factor in his choice to attend we cannot be sure just from what you've told us.
But nontheless he is investing his time at the university when he could be doing plumbing jobs and making money (or, by analogy, working on a startup that a certain VC has an interest in).