What organization is it? PSI?
I believe that there is a de-facto legal issue of teaching scuba for payment without instructor certification, or providing scuba trips for payment to non-certified divers. I'm fairly certain there is no analogous situation with regards to scuba cylinder inspection. If so, then many, many dive shops are in violation. Essentially the shops own compressors and are free to fill or refuse to fill any scuba tank they choose, as long as the tank has a current DOT inspection. Most U.S. shops choose to issue vis stickers annually, but who knows what training any individual 'inspector' has.
The organization I'm certified through is Scientific Diving International. I'm not saying your wrong about the legality of SCUBA instruction without a certification, and I would think it would be a really bad move from a liability standpoint, but I wasn't aware that the law recognized recreational scuba certifications. Read about how certification agencies are made. The way I understand it is if someone or a group of someones creates an entity and draws up guidelines for training and if they can get an insurance company to cover their instructors and if enough folks will accept their students as competent then a new agency is born.