Sure, there are some people who are not persuadable no matter what. But there are other people who are not crazy but who see stuff like this and have legitimate doubts.
Not everyone is a scientist or an engineer. You don't have to be an idiot to read the above statements and have your main takeaway be "they don't know for sure so they guessed" and it's completely reasonable to still have doubts based on that.
Anyway, probably just the inherent difficulty of trying to have a conversation online.