I've not come across any companies that pay for open-source work if thats not your primary role.
The reason that many recruiters ask if you contribute to open-source projects is because it shows you have a passion for software development, because you work on it in your spare time even if you are not being paid to do it. Therefore an employer is more likely to choose you rather than someone who just does it for a job.
The reason that many recruiters ask if you contribute to open-source projects is because it shows you have a passion for software development, because you work on it in your spare time even if you are not being paid to do it. Therefore an employer is more likely to choose you rather than someone who just does it for a job.