Linux is self-serving for them because it's the only way to not have to pay a third-party for licensing the OS. Enjoying the side effects of that is still fine though.
It's not a co-op. They're just relatively small and mostly hire senior developers who demand a higher level of respect and work/life balance. They used to only work on projects people had interest in based on consensus and personal interest. People floated between teams, you were free to convince people to work on your pet project instead, etc. They stopped doing that when they started on Half Life Alyx and talk about it in the design booklet because it also meant that literally nothing ever got completed since there was no direction and promising projects floundered from lack of support.
not to give any capitalists too much credit but often privately held companies will make better decisions for consoomers than traded companies which are gonna have an array of varying levels of rabidly money hungry capitalists calling the shots. like as if epic games would ever put out something like steam families.