Maybe the reason is that you keep repeating this meme which – although technically true – oversimplifies things and doesn't help with resolving unexplained experimental results. Sure, extraordinary claims require extraordinary proof, but now what? Should further experiments be funded in order to provide that proof, or should the unexplained results be buried, since there is no conclusive proof? Proclaiming "Extraordinary claims require extraordinary proof" is a way to immediately block this discussion.