I am 95% sure that you are right in this, and that I am wrong. The lingering 5% consists of 2 weaknesses in my own character-thinking-doing:

I like new technology, and want it. marketing works really well on me, and has led me to acquire things that I do not, on reflection, need. Things like knives, firearms, clothing, trucks, women...

I really did not see the nalgene/bis-Phenol A thing coming. I have cheerfully consumed a couple of liters of water each day from clear shiny nalgene containers. Felt good about it, too: cheap tap water, no disposables, and a blow against the loathsome marketers. So BPA toxoicity studies come along, and suggest that some plastics leach methyl-ethyl-bad-stuff into me. May be good science, may not. There is eveidence out there that asbestos and DDT may not be as bad for us as originally believed. Is the revisionist science better than the scary science? Is the
entire picture clouded by the interplay of science, economics, politics, ideology, marketing and scientifically-semi-literate me? Dunno. Will there be a study soon that demonstrates that the polypro shirt and fleece that I am wearing are causing brain damage, hypertension, and premature balding? (Clearly, something is doing so, or I wouldn't be the fellow I am today-it might be the clothes.) As always, the right answer is to just try to keep doing the next right thing, get advice from wise forum-dwellers, and react to the information as it comes available.

This much is probably true: George Mallory climbed all, or most of, Mount Everest in cotton, wool, and silk. whereas current climbers mostly use gore-tex, fleece and down. Lots of people still succumb to hypothermia, so it ain't just the clothes.