Well, it certainly helps that you happen to post about one of my favorite topics... people and the way people think. Fascinating stuff the study... or rather that science of the mind. I think anytime you collect data to determine cause and effect, it's science.
Even for a serious chef, there's a science to his craft... getting the right ingredients in the right order and amounts. And then, there's also an art to his craft... presenting the food in a way that looks pleasing. To which, for both, I lack the drive to cook in such a way that there is science or art. Just sustenance.
In a long round about way, what I mean to say is that for naysayers who don't believe that psychology is a science, the simple explanation could be that psychology to them is like cooking is for me. 😳