I think it's probably for stretch and to prevent felting (fulling). You will find this most notably in socks. 100% wool doesn't actually stretch and will felt (aka full) very easily. Adding a bit of nylon gives it that spring without having to do some strange weave to the fabric.

Shaker Village is awesome. Just chiming in with a tiny correction that the crafts are not made by Shakers. The Shakers refused to have sex as part of their religious beliefs, and consequently died out in Kentucky. Their crafts are awesome though and people continue to craft in their style. :)

https://shakervillageky.org/history-and-restoration

Yes. I live in Wisconsin. I have tried a few things and love my Baffin Escalades. They are the BEST. They are warm and the tread is amazing. They are also not as clunky as many of the boots I've had over the years.

I found Pajar to be narrow in the toe box and also have variable quality and fit between the styles. Kamik seems cheap, ugly, and not durable (some friends have had their boots but I never have).

A shout out to Xero for their Alpine boot, in case you like barefoot style shoes. I wear these until the temps reach 0* and then switch to my Baffins for the negative temps.