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.
Sure, you can put it this way, with the caveat that reality at large isn't strongly definable.
You can sort of see this with good engineering: half of it is strongly defining a system simple enough to be reasoned about and built up, the other half is making damn sure that the rest of reality can't intrude, violate your assumptions and ruin it all.