KIMBOKO: Natural materials are just, to put simply, better than any of the crap humans can invent. It has had millions of years to develop. Humans have only been around for 150,000 years, and have only been producing synthetic materials since after the industrial revolution. That is why natural materials are better. They do, however, tend to stop working properly when they are wet. Reindeer hair is by far the very best insulator, but the hairs tend to drop out if they are too warm (not surprising when you consider that they live in anything down to -50).
I think your opinion is similar to mine but I was trying to work out if anyone has come up with an explanation.
On the point of them not working when wet is not totally true as there are a lots of furry animals that although they get wet on the outside are totally dry on the inner layers. Toddy's sealskin for instance. Although I don't know if that property is carried on once cured or tanned.
I was wondering if the orientation of the fur makes its feel warmer by stopping all convection currents. Whereas with wadding or down there are small, open connected air pockets, allowing convection of heat. I just don't know.
I was thinking (and have for some time and still done nothing about it) of making a fur like cloak using a woolen pile similar to the Anglo Saxon cloth I've seen at Sutton Hoo. Or if not a cloak a sleeping type blanket/bag. I recently noticed that you can get or make an instrument to machine sew a looped pile onto a base cloth. This would save a lot of effort although not particularly traditional.
Just thoughts.