Is Human Reproduction Un-Ethical?

[Mudhammam]

But what is the point of continuing the human-species? Their contributions, if any, benefit only to themselves, but they themselves do not need to exist for anything. Nobody would miss us if we were all extinct. If we arose by chance and are here for nothing, this is the total sum of all that any of us can contribute, in the large scheme of things.

This is what bothers me most.

I don't follow. I don't think I can say that the world would be worse off if humans ceased to exist, and for many species it would probably be better off. But that doesn't translate to, "I need a reason to justify my existence" other than, "I exist," which is the source of meaning and goodness... for me, anyway, and hopefully for my progeny.