I think it's an issue with the marketing of it as well, I recently got notice that some of the most important open source projects I use have a patron page they depend on, yet didn't show it on github, only on their home page under donate. Same as with Kickstarter, if you want funds, you have to properly and visibly ask for it!

I donated a lot to git-annex because he did it right, showing everywhere that you could sponsor the development.