It's a hell of a good question.
One answer is ...people... we are all human; and looking for a way to game the system is about the most human thing possible, I know I've been there, done that.
Another answer is to do with the language we use - low carb, high fat, carnivore, plant-based, low calorie.. it's really much more about the effect on insulin.
And my best guess is that an honest conversation about insulin is so dangerous for the profit margins of so many corporations, that making sure we're all confused is the best strategy. Article after well meaning article... some truth, some nonsense, some random associations, but almost never consistent advice that centers on insulin.
200 years ago, we knew that "sugars and starches are fattening" (Gary Taubes, but it was on audiobook, so I can't find quickly the 18th century book it was quoted from).
Now, there's kind of a vague sense that it'll be fine as long as you have a pomegranate seed every now and again.
I don't mean that to be critical of anyone's choices (hell, I even like pomegranate seeds) - just that it takes so much work to have a real sense of whether that choice is actually a good one or not.