ZWExton I definitely think you're right on that ZW, if you're one of those players that like to switch your shafts around. But if you are one of these people, I think you are part of a very small minority of adjustable shaft owners who actually do so. None of my friends own multiple shafts, but that's a very small sampling considering that I'm obnoxious and I have few friends. 🙂
But I think there is an even smaller number of players who truly have reason and, more to the point, the knowledge to swap shaft out meaningfully. Again, a fitting will put you into a good shaft for you based on flex, weight, balance, etc., and once you have found that, why change? I think the adjustable driver allows people (and even entices people) to swap in and out shafts in hopes of finding the magic wand -- again, a cash cow. They do so without considering critical issues, such as weight. They just look at the letter on the shaft, which is bogus. Hell, they're swapping in and out shafts that are all building to 46"! Cash cow!
Of course, in discussing this, I am really thinking about the average golfer, who has average knowledge of golf equipment, usually derived from advertisements. But like ODE points out, on this board we are having a conversation among people who have above average knowledge about equipment. I fully believe that an adjustable driver may very well be effective in the hands of such people. You guys have a far greater understanding of what is happening when the adjustments are made and the effects they have on the specs and shot. You then least have a chance of making meaningful changes.
That being said, I have read quite a bit about adjustable drivers and watched Tom Wishon's video on them multiple times, and I still am a bit confused by them. It wasn't until very recently, when I was reading the adjustment specs on one of the drivers that I understood that increasing the loft actually closed the face angle. That is counterintuitive since we usually open the face on clubs to increase loft and hood them when we need a bit of added length. I don't think the average person has any clue about this.