A lot of people I know enter into a tertiary education without knowing exactly where they want to take it, and take opportunities and introductions as part of that course (much like specialties in Adv. O/W I guess) to guide them to their end goal. You could argue that a specific diving certification as well has a percieved value, not towards any particular gain, but as to personal safety and risk. You can get a job without a degree, just like you can enter a wreck without appropriate training.. both carry increased risk. One to your job, the other your health.
Just adding my peices in for healthy discussion
I used to be quite critical of the average LDS and PADI in general then I was politely reminded one day that I was appoaching the subject from the point of view of someone how was very pasionate about diving and preparred to take my training and skill level well past where Joe average would be comfortable.
With this in mind I'd have to say that PADI et al do an excellent job catering for mr and mrs smith who would like to look at the reef while in Fiji etc and that what I used to see as badge collecting and upselling is also avery effective way to get people to gradually increase their comfort zones and skill levels.
Whilst there are surely things that I don't agree with that the major agencies do, you have to admire the fact that they've built a successful system that spans the globe and has led to millions of people enjoying the underwater environment - even if that is for one dive every second year on a coral reef while on holiday.
Groups like GUE may introduce courses like REC 1 that cover supposed "flaws" in the way open water is currently taught but again you have to question the motivation of why someone wants to dive in the first place - I can hardly see Mr & Mrs Smith spending the time or a significant amount of money to learn to dive via GUE just so they can dive while on holiday (inspite of the fact that they would ultimately likely enjoy it more in the long run) Where you could easily see them do OW one year and AOW the following.
My only real bug bear with the industry was the tertiary training schemes that people got sucked into a few years back where multiple people paid huge amounts of money to qualify for jobs that never existed in the first place. As someone else pointed out the vast amount of equipment found on Trade me and repo auctions post that period clearly showed how successful the scheme was. In fact I actually new of one shop that was buying gear at Auction and re-selling it to the next batch of students at near full price.
Luckily the current economic environment has likely sent a lot of these businesses under and the dive industry is better for it in the long run.