That is not a reasonable argument. They have demonstrated nothing but a fear and postulation and we cannot accept authority as evidence. Thus is the nature of science.
I never said we should defer to their 'authority' either. But it is a conversation worth having, and the sooner the better.
If someone more knowledgeable than me on a subject fears it, well I think it's worth at least listening to him. Not dismissing his concerns arrogantly.
And when those person are one of the greatest scientist and one of the greatest entrepreneur of our time, both with some kind of expertise in AI, well...