Yudkowsky sticks out because he's weird and his position extreme, but by no means is his p(doom) representative of the increasingly-many worried researchers.
I find it tricky to think about cases like Yudkowsky (full disclosure I used to read LessWrong a lot), because if he has sufficient credibility then loudly staking your extreme position can indeed move the Overton window.
Yudkowsky comes across as the archetypal fedora-wearing nerd. His constant self-flattery is socially obtuse, his relevant credentials are entirely lacking, and his doomerism is an instant turnoff to a large segment of the public. He's a perfect example of the OP's "outside argument".
If Yudkowsky is moving the Overton window, it's in a direction opposite from what he intends.
I find it tricky to think about cases like Yudkowsky (full disclosure I used to read LessWrong a lot), because if he has sufficient credibility then loudly staking your extreme position can indeed move the Overton window.