I think it just depends on what likes actually are. Change them to “rec” for “recommend” or something and then they necessarily become public. But then adding both a private and public distinction for likes adds its own trap. “Oh you’re too good to like this publicly?” 😂

I’m a fan of the “putting flyers up in public locations” metaphor for Nostr. Following this metaphor, there are no likes, there’s only graffiti added onto the flyers.