I think "harmful" is subjective here. A diet recommended by "experts" and governments that suggests >50% "good" carbs is healthy is also subjective to me and the data backing it could also be described as "not back by any kind of knowledge...".

Harmful? No - you can't state that with any quantitative facts, what you've stated is pure postulation. The first thing I thought when I read this is that Seth's work and studies will be used as a scape goat to discredit the high cholesterol / high fat intake perspective on diet unfortunately.

"Generally not the kind of of crowd hacker news "associates" with." - It seems you haven't been here long.