For the most part people are in this business for the love of the sport and are helpfull, the problem with some is they love the sport but don’t know how to run a business.
One LDS was built by the father and then given to the sons who were freindly but didn’t want to be bothered selling things and would do their best to talk you out of things. They once broke my SPG while serviceing the reg and didn’t even want to sell me the replacement. What killed that shop is they didn’t service the compressor and got a reputation for pumping water.
My biggest problem has been with freshly minted DM’s who think they now know everything but have very few dives or only dive one location. There was an old DM with a lot of dives in a landlocked state who on his first ocean dive in Cayman didn’t know how to dive in a current, hadn’t listened to the briefing and went down current. The boat had to recall all divers to go pick him up!