>>49509303Arceus dislikes humans, and he didn’t like that Pokemons, who he created, liked humans, so he punished them by confounding their minds and language. The idea was that Pokemons in their current state would end up being subjugated by humans, causing them to grow to hate humans.
The franchise is about the love between humans and Pokemons ultimately overcoming that obstacle. It’s two things that are poplar in JRPGs: defeating corrupt gods, and the notion that love and friendship conquers all.