atheism and children

[Pyrrho]

I meant the decision to have children.  I made no comment on the morality of abortion.

When you decide to have a child, presumably, you are hoping that the child's life will be more good than bad, right?  But, of course, you cannot know in advance that that will be the case.  Maybe it will be, maybe it won't.  The thing is, you are taking a chance not with your life, but with someone else's life (your child's life).  It might be that it works out okay, but you are gambling with someone else's future when you make your decision.  That gambling with someone else's future is morally problematic.

To make the idea more clear to you, suppose I were to do something that potentially affected your future happiness, such that you could be very happy, or very unhappy, or anything in between.  And imagine I do this without your consent.  Would you regard my action as morally okay?  

The thing is, that is EXACTLY what one is doing when one decides to have a child.  One is gambling with the future of someone else, without their consent.

Can't it be simply because people have reproductive instincts regardless of how happy they want their future children to be?

An instinctual desire to have sex is not the same as an instinctual desire to have children.  I am inclined to accept that the former is an instinctual desire, but I have seen no evidence that the latter is an instinctual desire.  It seems more related to socialization than instinct.

Also, something being an instinctual desire does not mean that it has no connection to morality.  For the example of sex, consider rape and cheating on someone when one has promised to be faithful.  Having an instinctual desire does not excuse all actions based on that desire.

Since a fetus is not a life, it's pretty much irrational to talk about this. ...

That is irrelevant.  The decision is about whether or not to create a life, and the moral question is whether it is right to create a life or not.