> I don't think a ribeye steak from a grass fed, free range, antibiotic-free animal is particularly unhealthy.

It's unhealthy as in "not bringing enough diversity in nutrients". Kidney, liver meat are much richer sources of nutrients. Nothing wrong with indulging with a nice steak once a week, as long as you're having lots of plants/seeds/fruits-based meals as well.

Same goes for pets, but since you can't feed almonds to your cat, it's better off eating a mix of muscle, liver, bone marrow, etc.

I wouldn't worry too much about the cleanliness of pet food - it's been thoroughly cooked and processed to guarantee a long shelf life.