Sounds like he is building skills, thinking, and living life to me. He is failing at his current endeavor, but that is fine. Failure is good, builds character.
Failure is excellent, wish I failed in bigger ways as a child, it gets more expensive as you age. Continuing to work on side projects is a still a sure way to burnout. Side projects of pure personal enrichment (exercise, art, etc) are what repower a person for greatness.
We are discussing side projects in the context of taking a 9-5 job because of constant startup burnout from grinding. I am not arguing against side projects. Your comment was a cheap shot, offtopic strawman, who is going to disagree with your statement? No one.