Why not? Not giving birth harms none, i.e, even if people decide to have no children for egotistical/selfish reasons, no harm is caused. Meanwhile, to breed kids just so they help you with field work is well you are literally creating a laborers. I don't know about you, but it certainly does not sound good to me.
Yes, and the laborers they raised, brought another generation of laborers to the world. That was the life's cycle back then. However, who are you to claim it was done for egoistical and selfish purposes? What authority do you have to claim that? It's a matter of human beings struggling to survive and evolve along several generations, while passing their legacy ahead.
Life was harder before technology became available, but it's definitely not a reason to feel ashamed about.
Lol, that's nice burn, but in my defense, I would be perfectly fine in non-existence.
Well, then try getting some help. It's not a good sign to think such things.