I read the article in MD at the bookstore.
He makes a good point. He sells pictures at certain conventions to make money. OF COURSE, he doesn't want people to take pics of him for free (neither would any other bodybuilder who was doing the same). That's not smart for business purposes.
People also forget that he has a hearing problem and basically has to read lips to comprehend what they're saying. So, according to Ferrigno, some people mistake that for his being rude.