Domesticated = conditioned. Being a pet isn't a natural state for animals. It's like slavery for people. Once they have been continuously trained to behave in a certain way, that is what their biology (including mentality) will develop towards; from generation to generation. Just like certain "races" of Human beings have been subjugated by historical slavery, so too will they harbor subconscious inferiority complexes in the long run.
Anyways, I know you know this, and I know you agree here. I'm just adding to your point so that new readers can get it thoroughly.