Re: the efforts of hobby coders
You missed the point.
The bulk of the work in FOSS is off the backs of people who have minimal economic incentive.
Anyone can take an apache project code and embed it in to their licensed app with minimal requirements. (Why do you think companies like IBM like Apache licensing?) So you can take mySQL/MariaDB/etc and build/enhance a product that is no longer open source.
Fully open open source code is not going to make you rich. The exception to that rule is RedHat and its in an interesting situation.