I came from a mountaineering and backpacking background so my experiences have always been to only take what I needed through those experiences. My first tour bike was a Schwinn Sierra 700 hybrid. It did the job of getting me around until I got a "real" touring bike.
I also loved camping so fully loaded touring was just an extension of something I liked already.
I'm still using many of those things from lightweight backpacking and mountaineering to this day.
So I suppose I see your point but some don't have any background and will start from scratch. Buy all the stuff and either find out they love it or end up selling it on eBay down the road. Same goes for road bikes.... motorcycles, scuba and any other hobby people just jump into.
kyakdiver