That's a pretty weak argument. I love scifi, and I love for example Philip Dick's writing, yet I would not consider PKD's opinion on the future of AI/AGI particularly relevant.
James Cameron is not an authority on AI either.
If people said "Yudkowsky is a nice fanfiction author" it would be one thing. But he considers himself an actual AI researcher, and that's just not right. He is not qualified, and has no accomplishments in the area, other than writing fanfiction about it.
Here's a sampling of his non-fiction writing:
https://www.lesswrong.com/tag/sequences
https://intelligence.org/files/EthicsofAI.pdf
https://arxiv.org/abs/1710.05060
https://intelligence.org/files/AlignmentMachineLearning.pdf
https://arxiv.org/abs/1401.5577
https://arxiv.org/abs/1401.5577
https://intelligence.org/files/Corrigibility.pdf
https://intelligence.org/files/DefinabilityTruthDraft.pdf
https://intelligence.org/files/IEM.pdf
https://intelligence.org/files/TilingAgentsDraft.pdf
But you'll just say there's nothing of value there, and it's somehow figuratively "fan fiction", because he didn't go to college, and he doesn't work much on ML, which is clearly the end-all of AI.
Science fiction writers tell entertaining lies to amuse their readership. They are generally not really trying to "pain correct visions" of anything, and you are greatly exaggerating the extent they have success in this endeavor, which again, is generally not something they are even trying to accomplish.