A lot of people work on open-source projects that don't qualify to hold a job, whether it's a matter of being too young to work without a permit, not holding a pertinent certificate or diploma despite being fully capable of the work, or not being in a region that a given employer can hire someone from. Granted, that's not part of a free market and it's only due to protectionism that those conditions exist, but they are there to make other people richer, and the people in those conditions are not themselves rich.

There's also the matter that a median job holder in any field has plenty of free time, so you don't really have to be rich to work on side projects, whether they be model railroads, woodworking, or open-source software or hardware.

What about those who are in academia, students and professors working on OSS?

Are they already-rich?

It is impossible for open source software to be more elitist than proprietary software, especially if that open source software is distributed under a copyleft license.

I don't know who the uneducated individual was that posted this.

I developed open source software for 25 years even during the stretch when I was living in my car. I never made money from open source.