I don't use Google maps, so I'm honestly not really sure what their terms are
I guess in the big picture it just rubs me the wrong way a bit. I just find it mildly absurd that if I take a screenshot of OSMand on my phone and send it to a friend, that I've broken the law. It'd like to live in a world where that's not the case.
It's like if Project Gutenburg mandated everyone had to include a cover page with their name on every book they distribute. It doesn't make it unusable or horrible, but it's just a general feeling "ah, so close but they missed the mark".
It could have been a truly open repository of data and instead it's just so slightly not that (and in a way that's so minor that no one will ever bother to re-make a truly no-strings-attached version :) )