Earlier quoted context omitted.
I agree with you that 10X managers exist, but it's utter nonsense to claim that 10X developers don't exist. I've met people who are possibly at the 100X level; it's worth remembering that some tasks cannot be done by an average developer with any amount of time. I imagine that there are probably tasks that don't allow the 10X or 100X to show through; anything basic and repetitive enough (or so heavily specified that…
What's an example of 100X behavior?
Sometimes this also comes about by a deep knowledge of available algorithms and systems, so while a naive programmer might start flailing around like a dog with their head stuck in a bucket, an experienced person might recognize the problem as an Integer Linear Programming case, etc.
There are plenty of cases where no-one is 100x, of course.