I think the piece I’m confused most about is why the little free library website’s map isn’t the place to log little free libraries. That being said, it makes sense that OSM has guidelines like this in place to ensure the data quality stays, well, quality.

I feel like having such a map at all is kind of antithetical to building community. Shows you don't care enough to take a stroll in your 'hood to find such a one by happenstance (or to find neighbors to populate yours) and are hunting them down to share your self-published slop or something. Besides, it makes things a hell of a lot easier for griefers and trolls.