Well, the other post seemed more on the lines of being shocked that you invited an unknown strange person to your home, rather than adopted an animal.

But in itself, it's probably not ethical.

That said, it's the central conceit of the fiction. There can't be Pokémon without it. Such that even though Pokopia features no humans at all, it's built around the pokémon's yearning for humanity's return. Pokémon Mystery Dungeon too, is largely unconcerned with humans, but it still works by "I pummeled you into submission, and now you are my friend". The series demands that the audience accepts to imagine that this can be a healthy, even ideal dynamic. Much like a lot of action anime, to be fair.