If you're not already familiar with what OSM is, the copyright notice is really not going to be enough to alert the user to the fact that OSM works differently from commercial map data suppliers and can easily accept user contributions.

So when my grand mother has an issue with her app, she’s sure to notice that it says “open street maps” in the corner and go to the website, make an account, and contribute more accurate data? I don’t think so.

Really, it’s not even an age thing. I work in tech. I visit HN on the regular. OSM, Google, and Apple all have inaccurate data about my daily commute to work. They all say a path that exists doesn’t. Have I don’t anything about it? Absolutely not.

Imagine the average Pokémon Go user; if they even read the boilerplate that stood between them and playing the game, how many of them understood what role OSM data played in their experience, realized what the word “open” meant, and correctly concluded that they could do something to influence/correct the situation vs just thinking the game had a bug or glitch?

Also 99/1 rule. Inaccuracy can be not a significant nuisance/worth the effort/known to 1% who contribute.