Yes I do not know either I just look it the Mods work and we can see that many people ask nothing in return to the things they do because it is out of passion or necessity. I would too give my help to improve the software I work or play with often, it is in my full interest.
Regarding the quality coders, I agree, but we already know it will take less and less ability to do such things with AI, and more creativity that is much more easy to share.