Expecting compensation is fine. Demanding compensation is not, simply because it doesn't work: open source succeeds because those who contribute gets more collaboration and visibility than those who don't.

You can be compensated by "gorging" on other open-source that you haven't contributed to, working outside OSS, or asking for funding to keep working or work more. But if you work privately, you're competing against someone who will work publicly, while limiting someone else who would like to use your private work but can't afford it (like you can't afford others).