I've finally figured out the subtle difference between dive shops and surf shops that may be one of the keys to business success.
Surf shops respect the fact that you may or may not surf better than any of the staff. You are treated as an equal participant and the type of board you use, what draws you to surfing, and the way you express yourself in an aqueous medium is just as valid as theirs.
Dive shops do not respect the fact that you may or may not dive better than any of the staff. You are treated as an inferior participant and the type of gear you use, what draws you to diving, and the activities you enjoy are devalued if you weren't trained there or at least follow their philosophy.
While there are exceptions I believe this generalization sums up the experience as a customer.
Generalize much?