1) For his logic, I'm very surprised to see quite a lot of software are gratis - this includes many proprietary programs.
Actually many people are going to work for no charge - just like who are making bots or MODs here
However I don't think many people will _enjoy_ working in a big company with bureaucracy and takes away all the time and energy for him/her to do something he/she likes.
2) However this is still not the point - no one says free/"open-source" software must be "free" in price. You can make money - but only in a moral and non-obstructism way. And software at zero price are also _not_ all free software. Free software can be commercial and non-commercial software can also be proprietary. They are not related.
3) What's more, he's saying "open source" all the time, which only refer to an "bazaar development model" whose purpose is just making (technically) better software and nothing else. Maybe for him money is _much_ more important than a program which is technically more advanced but will bring him less money