Anything that challenges a ruling orthodoxy is mentally painful to most people and arouses their hostility, contempt, outrage, etc. Suggest that drinking cow's milk is quite bad for your health or that some vaccines are considerably more dangerous to your health than some of the illnesses they are supposedly going to protect you against...and many people will pretty much go berserk, because you are challenging some of their most basic and long-held assumptions...and that's part of their identity.

It's kind of like publicly saying "I do not worship Allah nor do I believe that Mohammed is the greatest prophet!" while inside a mosque in Riyahd or Mecca... ;-) It's more dangerous to do that there, of course. Even Chongo is not that reckless.