Which is why having one or two children is the recommended amount. Not only does it not overpopulate, but it also saves money. And your point is invalid because the whole human race is considered overpopulated, and as you say, it is egotistical to reproduce when humans are overpopulated, then NOBODY will have children if they care about it being egotistical and the human race will die out since the moment humans aren't considered overpopulated, most people will already probably be too old for reproduction.
And about your analogy, no, that is not what I meant. Life is a gift, even if it came from something horrid. And to celebrate that gift of life, you should not do that horrid thing, as it is amoral.