Maybe the better way to represent the disparity is with remainer average reward per post divided by leaver average reward per post rather than the other way around. In that case the correlation changes from -0.182 to +0.182.
I think the most likely answer is that rewards are not actually a major factor in people leaving. There's a wide range of other possibilities. Anecdotally, among my family the reason almost all of them say they don't use it is because it's too hard to use. I think we'd be unlikely to find that answer with a SQL query though...
This is true. Also, for users to actually have "value" in this community, they must go through the learning curve. Otherwise, the votes or any other activities they may wish to perform do not mean much and could be easily ignored if they do not stake, at least from their own perspectives. This attribute of the community creates a psychological fear that prevents them from starting the journey. Ironically, for network effects to take off for any social media platform, those "free users" could be critical. I think somehow the community needs to find a way to make them feel valued as well.
Also, if you have some extra time to continue the analysis, it might be useful to take a look at the reward Gini coefficients as a measure of disparity. That's what I will do for my paper lol