And not all hosts in the show are conscious. I would say that is a great metaphor for our current society, where you could say that the vast majority of humans aren't really conscious. They might eat and have sex and fight to survive, just like a host does. But they don't really comprehend what it means to be alive.

AI's, like humans, need a purpose. The best way of achieving that purpose is by self improvement so any AI which does not self improve to some extent will be replaced by another that will. Just like humans who don't care to self improve eventually don't reproduce enough to spread their genes.