This article is good, but not great - the author only gives one example of how quantitative-only reasoning can be bad (the example of the poppies). The other "example" is just the US military lying.
There are also no specific examples of non-quantitative reasoning that, if ignored, would be damaging.
There are also no specific examples of non-quantitative reasoning that, if ignored, would be damaging.
I feel like the Wikipedia article does a better job explaining this: https://en.wikipedia.org/wiki/McNamara_fallacy
Also, why is there an entire webpage dedicated to this?