- New startup, cool idea, not much budget to hire engineers
- Make it open source, piggy back on the free exposure that will get you, no marketing is needed because everyone loves open source!
- Your project gets to have top tier programmers as maintainers, make all the nifty features, fix all bugs etc. for free or at minimum cost
- Few months later, change license and/or close source it.
- Rinse and repeat!
Sometimes you get the community to fork it and maintain it by themselves, unfortunately, that’s not always the case.