You know, it's really a shame that people are so polarized.
DIR has a lot of excellent ideas. Bob has introduced me to some of them, and I read Jablonski's book, and I intend to take Fundies when I can. I have also been diving with Uncle Pug, who was not at all dismissive of the two novice divers he was helping to escort, neither of us remotely DIR. Neither of us remotely divers, frankly. The only experience of negativity or snippishness I've found with DIR divers has been on line.
I sat with the owner of our LDS today, and listened to HIM talk about DIR. He is very negative. He believes that anybody who says, "Dive my equipment or you are going to die," is saying this for profit-related reasons and it is regrettable (or worse). In the interests of harmony, I didn't point out that nobody says, "Dive my equipment or you are going to die." But I found it interesting that his perception of DIR divers is exactly the insular, cliquish, holier-than-thou attitude that has come up a couple of times in this thread.
We say in surgery that, if there are a bunch of different operations you can do for a given problem, then you know that none of them works particularly well. A really good idea has power, and spreads simply because it IS a good idea. One of the divemasters from our -- decidedly NON DIR -- shop dives with an octopus-length hose on his primary and his secondary on a necklace, because he thinks it is a good idea.
Bob's approach, which is to present what he does and wait for somebody to ask questions, is a superb approach for proselytizing. It's effective, and doesn't alienate the person inquiring.
For example, with my misconception about the aluminum tanks, somebody could simply have quoted the relevant section of the book that I misread, or (as was later done) given me a link to something written that addressed the misconception. Hellfire and brimstone preaching doesn't work very well when the congregation has choices