One of the things the tech economies try to commedituze is developers. While you sounding nice, the whole tech company push for "everyone can code" is an effort to commodetize developers. Having free and open source compilers and languages also serves to reduce the cost of entry and commodetize developers. In the past, developers would pay hundreds of dollars for compilers and languages (which is actually cheap compared to what other professions pay for their tools). Developers volunteer to teach new people to code. Developers spend their free time making open source software that is free for companies to use. Developers contribute to free languages and tools. Finally, developers complain that they are taken advantage by business people who think they are stupid! Software developers are the only professionals which actively work to commodetize themselves.
my sense is that a lot of developers create or contribute to FOSS projects in order to hone their skills and promote their own personal name (brand). they're trying to gain traction in the slippery, highly competitive landscape.
of course, they're also trying to make a contribution to the larger ecosystem, because they feel they've benefited from the contributions of others.
