Fair enough, but I wouldn't exclude the possibility that AI experts are biased for at least three reasons, namely (1) that they believe in some sort of sanctity

Fair enough, but I wouldn't exclude the possibility that AI experts are biased for at least three reasons, namely (1) that they believe in some sort of sanctity of the human mind (like many people do), (2) that they don't want to be regulated and (3) that they don't want to raise overblown expectations. There are definitely historical examples in which the majority of experts was wrong. I also find it incredibly difficult to tell what is missing about an algorithm. Perhaps multiple breakthroughs are necessary, perhaps just one (there is no good reason to believe that an algorithm that yields AGI can't be considerably simpler than what happens in the human brain). Initially, nobody thought that search could be done in O(log n) and similarly not many researchers expected neural networks to perform useful tasks until back-propagation was invented and demonstrated.