If the guy turns out to be a quack after all, I'd like to know why, not just be passive-aggressively told I'm wrong.
From the Wikipedia article on Greger, it looks like he may be cherry-picking his evidence or overstating his claims in some cases. Speculation, but that might be a reason people would disagree that nutritionfacts.org is a good source:
> Retired physician Harriet A. Hall, who is known for applying critical thinking to health claims, has written that, while it is well accepted that it is more healthy to eat a plant-based diet than a western pattern diet, Greger often overstates the known benefits of such a diet as well as the harm caused by eating animal products (for example, in a talk he claimed that a single meal rich in animal products can "cripple" one's arteries), and he sometimes does not discuss evidence that contradicts his strong claims.
Well, I suppose. Ariely has a good video on that people getting irrational as the topic moves closer to the body[0].
It's still pretty ridiculous given that just about everyone else is replying with their unsourced opinions.
And that's basically one guy whose critique is "he's a bit too enthusiastic about the plant-based diet." Given how attached people are to meat, that's hardly a strong counter-argument.
Yes, Dr. Michael Greger also sells books and DVDs through the site, but you need neither buy anything nor register to get access to all the material on the site.
Most of the videos are basically him summarizing a large number of papers on a specific subject. Each video is accompanied by a transcript, and sources.
[0] https://nutritionfacts.org/