In my humble opinion, it is much like scuba shops refusing to fill cylinders with VIP from competing shops or no sticker at all.
Then throwing the BS line that not VIPing the cylinder is against the law, or even against their insurance company's policies.
I was insured for over 20 years. There is no such thing as a 60 foot limit on open water divers, or a requirement for AOW to dive from a boat. There are unscrupulous dive shops who think that they need to screw the diver by making them get a VIP and an advanced card, and aren't honest enough to take the heat for the decision themselves.