Well I do what I can to encourage engagement and part of that is rewarding it. What's wrong with incentives anyway? People are busy and may well get more responses elsewhere, as you say.
Hive is different. There's no marketing division. There's no real management (apart from some on the technical side). Moderation has to be done by the community.
Despite what you say a lot of people just get on with being social and enjoy it. Each of them can be a marketing person who could introduce a few more people. Those will need some coaching into how it works. It's not easy and it takes effort. Without that we get nowhere.
Find your joy.