Fair enough, and I'll do you one better — many people who have children are unhappy.
It is true, and the main reason is that they had children for bad reasons. Many do it because that is what you are supposed to do in terms of expectations from society around you. Others do it to try to repair their bad marriage or empty lives by having children and so on.
Yeah, bloodline one, I have seen that too, not fan of it either. Let my bloodline vanish, not a bother.
It is a dumb argument as most bloodlines are trash, and many even have a lot of diseases. Do the world a favor and let it die out.