I don't think its a matter of past versus future. It's about doing your own research and ignoring marketing hype. In some situations wool is just better, even if down still works. In other situations down is just better even if fleece and wool still work. Marketing however, is always about making money. People should base their decisions on their own science and experience, not on marketing. Too much clothing and gear today looks like its for mountaineering, rather than other forms of adventuring which call for different solutions, and I would guess that most of it isn't that great even for mountaineering.

Cotton I don't care for, but it has its place if you are going to spend a lot of time near a wood stove as it is easier to launder. I will include a single pair of fleece boxers for this reason also, away from woodstoves. Generally I like to mix fleece with wool, plus light skin and shell layers. Wool is better for keeping on, especially as a sweater. Fleece is better for layers added and removed, but also might be better in snow as pants. It's hard to find good wool pants these days, loosely rather than tightly woven, so my main layers in winter is a hand knit wool sweater and 200wt fleece pants. Both wool and fleece have the advantage over down in that you only need to add or remove a light shell to make them alot warmer or alot cooler. Wool is the best material for absorbing and recovering heat from body moisture, but you have to be able to dry it out. If you don't have too much wool you can keep it dry just in the way you use it, so its sometimes absorbing and recovering heat from body moisture to keep the body warm, and sometimes drying out and keeping the body cool at the same time, from one part of the day or from one level of activity to the next. For hiking and camping amongst trees where wood for fire is available you might as well have a clothing system that can take better advantage of that without being too dependant on it. If sustained temperatures below 0degF are possible, even remotely possible, you need to consider incorporating some down into your clothing system. However, some folks might find a way to use down clothing effectively at 20 to 30F, and others might find a way to go without down clothing even at -20 to -30F. Depends on many factors. People need stuff that works best for the 90% of conditions they expect, but will also work for the other 10%, whether extreme wet or extreme cold or extreme windy or some nast combination of all three. People need to develop and test their own clothing systems. Most stuff that people wear today, even for climbing Mount Everest in my opinion, is based far too much on marketing and brand names, and not enough on personal research and experience. We should all endeavour to be better scientists and adventurers, not consumers.

It is interesting to note that even back in 1946 when Paul Siple wrote his paper, and I would guess even 50-100 years before his time, if not for thousands of year, there was always alot of heated and highly opinionated discussion about what the best cold weather clothing systems were even amongst experts. This is nothing new. What is new, perhaps, is post-modern consumerism. Then again, perhaps not.