It's really hard to tell what the motivation of any given free software author is. That makes it really hard to even know what incentives matter to any give author, team or community. It's just really diverse.

> That's true! But there is almost no incentive to have users; you pay a cost, but they pay nothing in return.

It's fascinating to see free software with huge user bases getting on with a tiny number of contributors. It seems like good code + near zero support cost + near zero support expectation seems to work.