The reason why NPS exists is because it's an easy number to calculate that sounds convincing, and manager-types love numbers without having to think too hard about how they got them.
That article just links to the wikipedia page. The main criticism paper[1] reasonably successfully debunks NPS as uniquely valuable, but more or less shows it as of comparable value to other measures of customer satisfaction.
Yes, that's correct. The broader point is that it's really hard to boil down something as complex as user satisfaction to a number. My time spent with UX professionals has taught me that all of these measures are lossy, and my time with data scientists has taught me that once you start depending too much on lossy measures, you're going to be led astray.
But management-types love little numbers like NPS, so it usually gets done anyways, especially in big orgs. And then it goes downhill, because PMs and leads are incentivized to optimize for the particular number their management chain tells them matters, and they game it because that's how people work. Later on, frustrated engineers and PMs who aren't a part of that game wonder if they're the crazy ones because they see very real customer frustrations brushed aside by an org structure that doesn't seem to care much about what users actually tell them anymore. Or they say they do, but never incentivize the rest of the org to address issues coming in through verbatim feedback.
Maybe, someone with the title of VP eventually wonders why a competitor is doing really well, looks at verbatim feedback themselves (it's usually been given to them already but they forgot about it), and then realizes they've been steering a big ship in the wrong direction, and causes chaos all kinds of chaos in the process. The sycophants in the org all line up to agree with them and declare they were right all along (and get rewarded at the end of the year), line managers and their reports are left confused because of the jolting priority shift, and people who might have felt vindicated by the direction shift are wondering if their leadership are actually fit to be leaders or not.
Is that all the fault of NPS or other numbers? Of course not! But they're an easy and generally accepted way for bad leaders to hide their bad leadership.
The reason why NPS exists is because it's an easy number to calculate that sounds convincing, and manager-types love numbers without having to think too hard about how they got them.