While it's good they do include some information about the use of their data, I still feel "public use" is not clear enough. For example if I build their data into my commercial product and sell it, is that public use? because it's totally okay to do that with OSM data.

Even with regards to attribution, we usually confirm that a listing on https://wiki.openstreetmap.org/wiki/Contributors is sufficient, because we can't guarantee each item will directly include attribution.