That sounds a very strange expectation. Most of my life post university I realized most of questions have complex answers, it is never as simple as you expect.
If the author would check how things biology and medicine work currently, I think he will have even more surprises than the fact that counting populations is an approximate endeavor.
I find the complication comes from poor definitions, poor understanding of those definitions, and pedantic arguments. Less about the facts of reality being complicated and more about our ability to communicate it to each other.
Apparent simplicity usually comes from weak definitions and overconfident summaries, not from the underlying system being easy.
Complexity is often there from the start, we just don’t see it yet.
If you're always chasing the next technicality then maybe you didn't really know what question you were looking to answer at the onset.
What's missing more often than not, across fields of study as well as levels of education, is the overall commitment to conceputal integrity. From this we observe people's habitual inability or unwillingness to be definite about what their words mean - and their consequent fear of abstraction.
If one is in the habit of using one's set of concepts in the manner of bludgeons, one will find many ways and many reasons to bludgeon another with them - such as if a person turned out to be using concepts as something more akin to clockwork.
Reality is such that, without integrity, you can prove almost anything you want. As long as your bar for "prove" is at the very bottom.