Not necessarily limited "intellect", but rather limited background knowledge.

Deming requires quite a bit of knowledge and understanding in failure/success modes. The core tenet of Deming is that every output is a result of some process and, therefore, output is controlled by controlling* the process itself. Look at your process and tackle failure modes in this priority list.

Drucker, on the other hand, puts the process under the fog of war and basically says deploy pressure on process outputs and let the process adjust itself. It requires much less understanding behind the processes to make sense.

* - Process control in Deming is mostly about variability.

that kind of ties in with the article's thesis; deming's approach is more scientific in the classic sense of taking observations and using those to build up your mental models, whereas drucker proposes a one size fits all recipe for managing roadmaps.

Deming -> Strategy

Drucker -> Tactics