Earlier quoted context omitted.
My belief is that for most of those people, no amount of evidence would have ever been enough. The entire "I looked at the data and found it insufficient" thing is by and large cover for people that lack the tools to evaluate the data. They play that card so they can pretend that they're actually intelligent skeptical adults and not easily manipulated idiots or malicious grifters. They're the equivalent of a random p…
"It was developed in the last 6 months" and "It was developed 50 years ago and millions of people around the world have used it with no ill effects" doesn't really require a degree in biochemistry to evaluate the possible risks.
Instead those supposedly literate people pull out percentages so blatantly incorrect that any attempt to convince them turns into evidence for the validity of "Never argue with stupid people, they will drag you down to their level and then beat you with experience".
You see this all the time on social media, with the most recent version being rabid antivaxxers pretending that 80% of to be mothers that got the vaccine had miscarriages.