You're being pedantic. The users point is that neither the Linux foundation, Linux Users, or Linus Torvalds pays people to contribute to the kernel.
While one company may pay its employees to write code for the Linux kernel, that company is still writing the code and contributing it to Linux for free.
- were payed to work on GNU/Linux by their employers
- had a different source of income
- were students with their parents paying for their bills
- were building a portfolio for a job change
So money did change hands, even if indirectly.