alt Hacker NewsIt goes far beyond the manosphere. You can find people selling all sorts of naturopathic, homeopathic, crystal, and Jesus endorsed medicines.
Anywhere a group of people gathers to downplay pharmaceuticals or evidence based medicine, you'll find them pushing their own untested and unregulated junk.
I think you have the cause backwards. Anytime people can make money pushing their own thing they will downplay evidence based medicine.