I've thought about this for dogs. I've never had a cat, but some of this probably applies, with the complication that they have a somewhat sour temperament as well.

It'd be nice on one hand, because I could say "chocolate will kill you, don't eat it", and they would know I'm not just being a chocolate-hoarding bastard. On the other hand, they couldn't get away with pooping in front of everybody. They get leeway on things like that because of what they don't know. It seems like a slippery slope where, yes, they would end up being treated more like older human children or human adults, and maybe that would spoil the cuteness a bit.

It's worth noting, I think, that historically dogs were expected to work for the most part. When food is often scarce having an extra mouth to feed for fun is conspicuous consumption. Often dogs were the food, too - we're the weird ones eating pigs but never contemplating eating dogs.