When you have a kid, that kid isn't you. At all. So the kid is not your immortality. The kid is their own individual. It isn't fair to make your kid into an extension of yourself.
Sigh. That wasn't at all what I was trying to say. I'm not my father either... but a piece of his generic code is in me. He was the final link of a countless chain of beings, and I am a continuation of that chain, and my daughter will be too. I hope that makes it clearer... unfortunately I'm not enough of a poet to express this sentiment any better.