Thing is, I'm not a "storm-bound climber", I'm a hiker and backpacker, and I tend to not be hiking or backpacking when it's raining, so that "Science" doesn't really apply to me anymore than the science behind Kevlar, which I also don't wear while backpacking or hiking because no one is shooting at me.

So I still offer that this is a style, regional, and conditions based decision and there is no single solution that is best for all styles, locations, and conditions.

My style is bushwhacking off trail, the region I do this in is filled with bramble and briar and sharp rock, and the conditions I go out in are generally not when it's raining, or even much of a chance that it might rain. For that, cotton works great, but I still bring a lightweight backup of wool/fleece inner layer and a waterproof outer shell, which bring us back to "be prepared".

When it's really cold I wear fleece lined denim jeans. They're awesome for bushwhacking around here. They're heavy, but you can trudge right through heavy briar and not get ripped up.