The thriving open source community that has been in existence for the last two decades, run and supported by (mostly) otherwise employed engineers, and used in countless business support areas worldwide, is the most amazingly obvious evidence against it. It is so large an elephant in that paragraph's room that I'm not sure how anyone could miss it.
I was making the point that open source is not a competitive way to do business, it's essentially giving away to other programmers of other companies, and it's fine if everyone is making money, but it's not always the case.
Investors will want to own something like patents or source code. I'm not saying it's not impossible, I'm just saying it's only viable in a minority of cases, because capitalism and business management works that way, even if I don't like it for other reasons (patent trolls).
What bothers me the most, is that open source or free software is not a proper way to employ people and build businesses. Writing software requires time and efforts. You're giving the example of employed engineers, but what about the rest ? Engineers are a minority of programmers, they're employed, what about the unemployed who want to make something? Just contribute some patches and hope for an interview ? Sitting in front of a computer for hours won't land you food if you're not paid for it.
You talk about community, but honestly I don't really cares about the community. I care about technological progress, competitiveness, and people able to have a career in the industry. A community can be pretty exclusive.
