We are all going to die and most of us seem to want to create successors. If artificial progeny are more successful than the old method, then perhaps that is how it will go.
I was listening to Ezra Klein's podcast on the subject awhile back. He talked with lots of AI researchers and was surprised to learn that many of them did see a (small) chance of apocalyptic outcomes yet persisted with the work anyway. He was puzzled by this, but to me it's quite simple - these people are engaged in the oldest of human endeavors; creating children. I suspect that the risks are acceptable to these people; what would you do for your own children?