Let me take a stab at this without the extreme flamming.
1) I was trained through padi all the way up to rescue diver. Their teaching is very promotional toward BC. They like things done their way.
2) The information is not as available. To the diver that flys down to the Carribean and dives in 100' vis, they are happy for what works.
3) Since DIR is not taugh from the beginning, people are going to go with what they know
4) Recreational divers do not spend the time reading about deco theory, bubble formation and dci. They just like to dive in clear water and kick around.
5) Many divers, like myself, buy all the gear they need before or directly after their open water class. I was not happy to find after spending my savings on gear, that there is a better setup.
6) To go along with point 5, The money is also a problem. I am only a college student without the ability to get a job. Money is very tight for me. I do what little side work I can to earn some cash. I thougt I was doing great by saving up, and buying my bc and reg. I did the whole ebay thing too. I spent almost everything I had on dive gear, then I learned there is different way.
7) Even in the tech diving community, if you have a parnter with a ranger or other "hi tech" BC, then it eliminates you going to the DIR setup b/c of your partner.
8) The attitude is more is better when it comes to marketing. If a good salesman at a LDS gets ahold of you, you can walk out with a bunch of crap that you will never need. LDS promote the "tech bc" b/c it has 25 d rings on it, ajustable lumbar, integrated weights, trim weights, heavy nylon, and whatever gizmos they now sell. More crap sold = more money
9) Looks are a big deal, though pointless at that. I hear many divers when I try to explain my bp/wing setup, they just turn the other way b/c of how it looks. I may look uncomfortable, like nothing is there, it is too redundant, or whatever excuse I have heard.
These are just my opinions: I am only a rec diver right now, b/c I do not have the experience nor the training to be called a tech diver. I have been reading alot about dci, bubble formation, deep diving, bubble solution, gas mixing, and deco theory. I am very eager to learn anything that anydiver is willing to share. I will never belittle a diver for something that works for them. I have learned to keep an open mind. I used to dive the pseudo tech BC, but i have my Fred T plate on order, and a halcyon wing waiting to be mounted. I am taking classes on deep diving, gas blending, and general tech issues.
I have yet to go to the DIR setup b/c of the money issues right now. I am scraping by to pay for rent, and classes, so scuba comes when it can. I will be using the DIR setup soon, or at least most of it.
I do not mean to degrade the BC users and if I have I am sorry. I used the BC to BP as an example because that is what i have personal experience with. I do not have the 7' hose b/c it is not in my budget at the moment (thanks Fred Taggie). I know that a 7' hose and a BP does not make someone DIR, but rather the attitude and need to strive for perfection does along with gear config.
WHY DO PEOPLE NOT USE DIR? SAME AS WHY PEOPLE DO
People are entitled to their opinions, and each has their own expierences.....some like coffee, tea or hot cocoa. some are christians, muslims, or jewish, or some are for the federation while others are keen on assimilation.
TO EACH HIS OWN>>>WHETHER WRONG OR RIGHT!