I nearly down-voted this question because every time funding and open source come up together, there will be a lot of arguments about it. But to answer your qu

I nearly down-voted this question because every time funding and open source come up together, there will be a lot of arguments about it. But to answer your question: Debian maintainers are not paid to maintain Debian. People volunteer to work on the Debian project because it's something they use, love, and believe in. Working on Debian is where they get their passion and joy, money comes from somewhere else. A few maintainers few _might_ get paid by their employer to work on Debian packages that the employer has a vested interest in. As an example, there were some Canonical employees who were also Debian maintainers, but I don't know if this is still true today. I think there are a few companies that tend to hire established Debian developers, like Freexian.