I do believe it when Apple says they're respecting their users' privacy, just like I believe it when DDG says that. But I am disappointed when I see how these companies neglect freedom and how so few of their users care about it.
Another big argument for supporting free software solutions is to do it for the people who want/need freedom (like whistleblowers or activists).
You are still free to do that with OSM. Not sure what that has to do with DDG. Just because they don't want to use OSM, doesn't change any of your rights to using OSM.
> Apple on the other hand is hoarding its information.
You are free to requisition a fleet of mapping vehicles, drones and satellites and gather your own maps information and share it with whomever you want. If Apple is the one paying a ton of money to create their information, I'm not sure why it's surprising that they want to use that information in their products.
You don't have a right to Apple's mapping data any more than you have a right to Colonel Sanders's chicken recipe -- however, nothing is stopping you from making your own chicken recipe and sharing it with whomever you want. You could even start a community around sharing chicken recipes. That some people don't care about chicken recipe secrecy doesn't harm your rights to enjoy chicken with recipes created and shared by you or your friends. Some of us actually just want to buy some fried chicken and not worry about the provenance of the recipe. We have more important priorities (for us) than the openness of a private company's chicken preparation secrets. We just want good tasting chicken. Many of us aren't chicken enthusiasts, spending our time lamenting the secrecy of the Colonel's chicken choices.
What it really sounds like the source of your complaint is that if DDG doesn't continue to use OSM, then perhaps OSM will suffer for it. If that's the real origin of your disdain for this decision, then perhaps OSM isn't as valuable in the marketplace of ideas as people might think it is. However, if this actually doesn't affect OSM (I don't think it does,) then that means that DDG can use whatever they want and the OSM folks can happily share to their heart's content.
I'm not saying Apple does nothing for the open source scene. In fact, they're maintaining some important projects (like WebKit). But when you have billions of dollars that you don't know what to do with stored in some offshore haven, you could do a bit more.