Because the are extremely reactive, cause inflammation, ROS, MDA, peroxidation products, suppresses the immune function, carcinogenic, estrogenic. More importantly, they prevent the oxidation of glucose, poison beta cell and suppress thyroid function. Gee what's to love about them.But why does he avoid PUFAs...
My husband is terrified of prostate cancer and checks everything that comes into the pantry from the supermarket shelf. Zero vegetable oils, even olive oil but plenty olives and loves his sat fats. There is no way you would convince him to take flaxseeds or heaven forbid the oil to prevent prostate cancer. Absolutely, no nuts. He is also the specialist in mycotoxins and can tell you precisely how much is in nuts and it is never zero, even in organic ones. The worst grain is maize, many people on this forum would not be eating maize, however, it is fed to animals when levels of mycotoxins are just too high to be used by the food industry. Huge semi-truckloads of toxic grain ends up as food for the animals we eat. However, what goes into pet food is clean. That is pet-food from the industry leaders; can't vouch for smaller manufacturers.
You should not be asking that question as a member of this forum.