Wow, you two have been watching JFK too much or reading too many conspiracy theories.
LK -- "Club" is not an optimal name, but for legal reasons it could not be called "association" at this point. My point was exactly what you supposed -- that club makes it sound like a bunch of guys with a six pack and some tanks that want to go diving. It is, however, a government/business group who's objective it is to promote Pattaya as a wreck-diving destination and to secure government support for getting additional wrecks sunk in the area.
The two blog posts on the site from last year explain that.
Apeks -- Time for a chill pill. The PDC is an association whose main reason for being is to promote Pattaya diving at trade fairs and through advertising AND lobby the Navy and government to secure additional wrecks. It is only that and has nothing to do with anything else.
Also note, membership in the club/association is open to anyone -- not just dive shops. However, dive shops, the Tourism Authority of Thailand and PADI are full founding members while individuals and companies with an interest in diving can join as associate members. There are minimal fees of a few thousand baht (at this point) to join.