Also I don't get the point why you would want them easily scrapeable to begin with. If you have eyes to read and can walk across YOUR neighborhoods, you would have eventually seen one. I thought that was the whole point? They are not exactly hidden. I find those public bookcase incidental low barrier offerings to a reading exprience you just stumble upon, nothing you would seek out on a map.

Why would you want to have more people from anywhere else possibly raid them for anything useful? This way nobody is inclined to put anything worthwhile in there if it just ends up outside of their communities. Not that I'm in general pessimistic, just would like to know what is gained by putting the exact location into a map and not just have a list of neigborhoods with a book corner and optional photo on that neigborhood level, if people want to network around them.

Those people traveling to them are probably just as likely to put something in as a more local passer by. And I'm not sure why I would care that someone the next suburb over read my book. As long as someone is enjoying it, that's the whole point of donating.

Recently it's seemed like (very roughly) half the Little Free Libraries I see aren't in OSM.

I sometimes edit OSM, so I'm wondering whether any public bookshelf omissions are intentional, and adding the shelves would be unwelcome by the people running them.