Great question that I think could apply to more than just the games.
There can be a ton of contributions to a home-brew title. Programming, music, sound effects, game art, packaging, marketing materials, you name it. I think there's always been in place a sort of "gentlemen's agreement" with the programmers (traditionally the project owner) and the contributors. We're all happy to pitch in, and give up any rights to our contributions, in an effort to keep the scene alive and ensure the hobby thrives. Is that hobby is now in the hands of a corporation that stands to make a profit from past contributions?