Yes, it's fantastic for indie game developers no doubt. After having a catalogue they can get a good paying job and build a career. Musicians, on the other hand, only get offered more exposure gigs.
This is not an exposure gig. Some artists chose to publish their work as CC license (like some devs publish under open source licenses). This site allows them to upload these works, there are plenty of site that offer the same thing such as https://commons.wikimedia.org/wiki/Main_Page
So I know a few musicians who release for free. All of them have day jobs as software developers, designers, and one really cool guy who is a C level exec.
If music is your career, sure you have to get good fast and sell at every opportunity.
However don’t discount how good you can get just jamming out with friends for 30 something odd years.
