This seems to be a characteristic of many high functioning people, especially successful engineers. There is a "correct" way of living your life, conducting your business, using your text editor, etc. It's helpful in that it ensures consistency and focus. The downside is that people become desensitised to nuance.

In this particular example, the word cargo in cargo cult is redundant. All cults have ridiculous ceremonies for cult members to engage in. These ceremonies come from human nature, our inability to distinguish correlation from causation. We're told to conduct a ceremony, get a good outcome, then believe it's the ceremonies that caused the outcome. Just call them ceremonies, because that's what they are.

However, when Feynman wrote his speech he must have thought that a cargo cult is a much more graphic metaphor than a dry lecture about stats and human biases.