There are forums of people that take the viewpoint that the world is a disc and that the media is run by shapeshifting lizards, too. That doesn't mean they deserve to be taken seriously.
>"people who think that excess sugar is bad for you"
Parent is referring to people who think polyunsaturated fats are bad for you, though. And what I'm taking issue with is the argument that because there exist 'entire forums' of people who have accepted a claim, their views should be given credence.