Wouldn't surprise me one bit.
Very few people make it to that level by being nice.
Of course Joe used whatever means he could find to promote his business. He bought a lot of his fame by paying famous BBers to use there names. He personally didn't pickup scrawny little kids and spend every waking moment training them. Arnold was already a pretty big boy when Joe started paying him to work for him. Same with the others. All the big boys trained in other gyms, and learned from other lifter's, bodybulder's and trainers. In all fairness, Joe did help there careers. He showed there photos and told there stories to thousands. He among others boosted there careers to a point that they, on there own, might have never achieved. Joe will always be an icon in muscle history. He is not the only one that made money off the big boys. Look at all the company's that paid Arnold, Franco, Dennis Tinerino, and many others to be shown in magazine's with there stuff even though they never used it. Arnold, Franco, Dennis and others owe equal thanks to guys like Bill (peanuts) West, George Frenn, Terry Todd, Powerlifters that trained with them at gold's, Zuver's, Bill Pearls Gym, Muscle Beach and more, also taught them how to get massive gains. Trainers like Joe Gold, Leo Stern, Bob Zuver, Bill Pearl and many others helped these guys become great. It's never just one guy. But it does always become about the money. Some of these guys may have never gone as far in the business had they not found that financial support. After all who wouldn't love to train for free and get paid to do it?