One aspect I suspect comes into play is the effect of the internet on all this. When I began touring (I guess late eighties), I had camped all my life growing up, canoe trips and such, so "bike" camping wasnt that much different, just a diff set of bags and using a map. In other words, I kinda just winged it at first. I then used the resources of a biking organization here in Montreal that had a small library of books on bike touring, so I kinda winged it but had the books as references a bit (like when I went to France for the first time for example).

that was about it though. Nowadays, one can find an amazing amount of info on the net about, well, everything. One also can go hog wild and obsess about every detail cuz "the forum" say you need this, you need that, well, you get my drift.
Throw in the aspect of "social media"--izing a trip, writing about your preparation, your route, what your toenail looked like when you dropped your loaded pannier on it on tuesday morning....sort of stuff, and the experience can be very different than pre-internet.

dont get me wrong, I still find the web to be an amazing resource, its so neat to be able to get info on this that and the other thing, and planning a trip is so much easier, or should I say, one can find out more stuff that does make life easier. I do think however that (going back to your point and example of the person spending months recounting the prep) perhaps some people get too much into the "social media" aspect of it (perhaps not a good way to put it, but all I can think of) and also get too much into "having to buy this that or whatever".

re: stuff collecting dust, I would counter that with the fact that with the exception of a few things I own, most of my bike touring stuff gets used for car camping anyway, and even with kids, has gotten used for ages for outdoor stuff in general. Other than my Whisperlight, which for car camping got replaced by easier propane stoves, campmats, tents, clothes, all got used anyway. Panniers were always used for commuting, and any other bike stuff (except maybe front rack) was used when biking here and there.

I guess in this respect, I look at it in a positive way, that (hopefully) folks who try bike touring will do more outdoor stuff anyway, so the stuff they get will get used. I figure if someone gets all the crap and either never did outdoor stuff before, and doesnt afterwards, well....dems da breaks, and too bad for them. I would hope that most people like it and do do more outdoor activities.

but I do stick to my view that the web probably increase the number of people who get all gangbusters about bike touring, and then might find its not their thing, but perhaps got too much into "oh I have to have this, or that..."