Wouldn't that just eat up a lot of their valuable existential-risk minimizing time? I might be stealing an idea from Hopefully Anonymous, but I'd ideally like to clone large numbers of the most effective minimizers and devote every waking hour of theirs to minimizing our existential risk (really, maximizing my odds of persistence, but that goal won't get as many other cloners to buy in). In the absence of that kind of control, convincing them that they can never obtain partners and should just give up would be second-best. I believe Narses put so much effort into living on through his accomplishments precisely because, as a eunuch, he could have no progeny.

On a related note, I've got a post saying we should be grateful for diversity-induced anomie. Bryan Caplan & Mencius Moldbug have both had interesting things to say on the virtues of abject surrender.