There are some exceptionally stupid pokémon out there.
Rhyhorn would be one example; "A Pokémon with a one-track mind. Once it charges, it won't stop running until it falls asleep. "-Yellow Pokédex entry.

Then, there are pokémon which are far more intelligent than humans could ever be, or ones which can see the future, and are thus able to make far better judgements than their trainers.

Yet, they all obey the commands of their trainers instantly.
Why is this the case?

Please no "It's a game and it would be less fun otherwise.", I know. This is supposed to be a lore discussion.