Opinions aren't genetic, so that's not very good logic. I guess the logic depends on a culture passing on a value - by means of words, not by genetics - such as spawn furiously to the next generation, who accept it uncritically. That would be a version of (2) I guess: mindless reproduction along with hostility to thinking about it, with memes as the mechanism. This memetic condition would tend to win, you'd think, except somehow it hasn't won already, and we are still somewhat mentally capable of considering our reproductive options. Perhaps having children thoughtfully is the only effective way, and so it must necessarily be by choice.