...you're on Hacker News. A significant portion of this website is just people talking about Open Source Software, something that consistently produces case studies about people making things for love or for art or for passion instead of just for money.
Plenty of people make things for value that isn't purely financial.
> Otherwise they wouldn't copyright it.
This isn't how copyright works, at least in the US. Generalizing broadly, you own the copyright of whatever you create unless you've otherwise signed that away. It's automatic. You don't fill out a form to have copyright over a work.