I read that as a statement of arrogance. We are not überprogrammers able to delve down to all levels of the system.

When was the last time an Excel macro developer needed to know semiconductor physics in order to debug a fault lying in the silicon layer?

When has a Ruby on Rails programmer ever needed to know quantum electrodynamics to track down a hard disk error?

Abstractly you may consider that knowledge to be useful, but concretely, there's a reason people specialize - each of those domains takes years to gain competence, and there's a good probabilistic argument against everyone being "able to jump to level N - 1" all the way down.