Babies are obviously nothing like pigs, because fast forward a year or two and one is talking to you whereas the other never will. And they are talking to you because of something that happened in that year or two, and it isn’t something that happens in pigs, ever. This is not a small difference, it is a radical difference.
Enacting an anti-rational meme causes other people (typically one’s children) to lose the ability to think critically about the behaviour in question, and to become unable to refrain from enacting the meme themselves.
Karl Popper’s theory prevails because it solves problems other theories of the growth of knowledge fail to solve, it is a better explanation than its rivals, and it unifies ideas previously thought to be unconnected.