Gaff had his share of feuds. Plus he pissed off a lot of store owners pushing the Z-90 stuff that pretty much nobody wanted. I only met him and didn't get to know him, but back then everyone had a story about him, to say the least.
The NASDS approach was to offer the most complete basic certification course possible, making solid divers who really didn't need another course. The stores would make their money pushing equipment, i.e. SCUBAPRO. The PADI angle was not just equipment sales, but on upselling every course possible. All those PADI patches were a powerful selling tool, and made the diver want more. NASDS, in general, produced more qualified divers out of the chute. But the PADI methodology, in terms of a business, won out because they made more money for both the instructors and the stores. I was a solid instructor, but a lousy salesman, so I didn't make much money and therefor the store didn't make much money. Not trying to badmouth PADI or the instructors in any way, by the way. Just a rant about how the best training doesn't always equate to better business, unfortunately.
Just putting in my two cents cuz I miss talking about this stuff....