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?