Interesting thread, some fad items I duly concur with, others I don't.
Fire Pistons and roof tents jump out to me as being the most faddy of the camping/bushcraft fads.
I don't agree that Swanndri's are a fad though, I adore my ranger shirt and know a lot of people who feel the same and have used theirs for years. Wool, in whatever form it takes, will always be cool!
Some chat on this thread does illuminate an underlying issue with this hobby. Bushcraft isn't quite what it used to be and things have become all too commercialised. It's far too easy for us to become a little kit-p!ssed and obsess over the latest and greatest bit of kit when what we really need to do is contine to learn and develop a better understanding of our natural environment. I duly acknowledge that my own youtube channel is somewhat guilty of this, but do try to retain some semblance of bushcraft and skills practice.