It's a perfectly coherent question! I'd kindly ask that you try to comply with Hacker News's guidelines about engaging in kind dialogue, and specifically the line "please don't post shallow dismissals".
Here's what I consider to be a simpler question to answer: do you think people have the right to give birth to a child whose existence would be only horrible, endless suffering before eventually succumbing to death?
This isn't just a hypothetical: people tend to agree that a parents who are at high chance of birthing a child with a terrible genetic disease probably shouldn't take that risk (or, at least, should protect against it with some preimplantation genetic testing).
But everyone suffers at least a little bit at some point in their life. If you don't think people have a right to birth children whose lives would be pure suffering, but you do think people have a right to birth children who would suffer at least a little bit in their lives, then how do you justify one but not the other? Is there some threshold amount of misery which you think is okay to inflict on someone without their consent?
There may be some other moral framework or argument which articulately justifies this, and I'm genuinely curious to see if someone has come up with an interesting answer to the question.
It's a legitimate question! Many people wish they had never been born. What right do you have to force such a person into existence without their consent?
That question is incoherent.