"because Eliezer is probably the world expert on AI risk"

There is no experts on the AI risk. There's nothing where to get expertise from. He read some SF, got caught on an idea, did not study (self study or otherwise) CS or any actual relevant body of knowledge to the point of producing anything useful, and he is a very convincing writer. The experts, you'll get experts in 2050. He's a dilettante.

People follow some sort of distribution on their risk estimates. Eliezer is just the far far off end of the bell curve on the risk estimate for AI, among those with writing skills. He does make some interesting points, but he's not a risk estimator.