I'm sure we need to do something to make scuba more visible and more appealing across the board.
No matter how good a national or international marketing campaign for diving is, it will founder if the experience the customer has with shops and charters is negative.
You do raise a good point, but do you think the success of the MilkPEP campaign (or most any campaign) is dependent upon the business practices and attitudes of the people employed on the retail front lines? I've never worked on a campaign where people said "How are we gonna sell more beer -- everyone knows that bartenders and liquor store employees are sort of dopey, annoying people" or "Who's gonna buy lottery tickets - no one wants to shop in a convenience store." People don't buy billions of gallons of Coke, Pepsi, etc because they like the pleasant attitudes of fas-food servers and grocery-store cashiers. (I know these are very different cases, and LDS's should be more adept at customer service, but the point is that in any line of business, high demand for a product makes a lot of other business problems go away, while making the other problems go away will NOT create higher demand.)
If there were to be an effective campaign to market scuba, the creation of demand - and itch the consumer wants to scratch - will drive people to go find a different shop or put up with the BS of a convenient shop because they want to dive so damn badly...