Why do people say such silly things?

I saw someone say on here yesterday that all psychics and mediums are 100% fakes because nobody has ever proved scientifically that these sensitivities to energy are genuine. Well, surely nobody has proved God exists yet billions of people believe in a god. We couldnt explain or prove the earth was spherical not flat, because science wasnt able to explain it at that time. So is it not a little obtuse and rude to expose your ignorance on here by making these claims about people who do mostly very good work? For the record, Im a medium, I dont charge, I do it to help and heal people. I also do it because I know Im not lying, and I know there is an afterlife. I want to heal people from their grief. I dont have any mental problems, in fact I hold down a very professional job. Before spouting off, please think about what you're saying. Or maybe you think Im still one of those 100% fakes...?