If everyone did that, there's a non-negligible chance the human race will die out before bringing about a Singularity. I care about a reasonably nice society with nebulous traits that I value existing, so I consider that a bad outcome. But I do worry about whether it's right to have children who may well posess my far-higher-than-average (or simply higher than most people are willing to admit?) aversion to death.

(If under reflection, someone would prefer not to become immortal if they had the chance, then their preference is by far the most important consideration. So if I knew my future kids wouldn't be too fazed by their own future deaths, I'd be fine with bringing them into the world.)