It goes deeper than that for me. If it were an actual $10 app, I would be more interested. Pay once, and everyone in my family could play courtesy of Apple Family Sharing. But by making the unlock an in-app purchase, everyone in my family would have to work over $10. And then there's in-app purchases beyond that.
I almost bought it anyway because I'm about to fly internationally and would have enjoyed the diversion on the trip. But to combat privacy[sic], Nintendo requires an Internet connection to play. So that use case is out as well. That just doesn't leave me with a lot of value for $10.
If it were a regular $10 app and there were some modes I could play offline, I would have bought it at launch.