"he is not one to take things personal, and seems like very experienced and tried individual with thick skin"
I don't think that's true. My sense of him is that he's a person with good and valuable ideas about human biochemistry, but just plain lousy at communication and people skills. I think he truly is clueless about why people react to what and how he writes, but I don't think that cluelessness has to do with thick skin. It has to do with an ignorance about how to communicate. His jaw-droppingly brusque posts, juxtaposed with his "smile tis your choice" signature is a classic example.