Are Hex Signs Just Decorations? Or, Is It Pow-wow?

I live near what we call Pennsylvania Dutch Country. As you pass by the many farms you will see Hex Signs hanging from barns and houses (and other items) along the way. Hex signs were always seen as to ward off misfortune and evil spells. But, over the years there have been scholars arguing of the true meaning behind them. Many want to see them as "ethnic symbolism". The signs are only used by the Fancy Dutch, not the Amish. There are even people called Hexologists that say these signs are rooted in traditional folk art, such as "distlefink".
Pow-wow is an American folk religion and magic associated with the Pennsylvania Dutch.
There is a book called Pow-wows, or The Long Friend by John George Hohman in 1820. http://www.scared-texts.com/ame/pow/index.htm . Despite the Native name, from the Algonquian Indian word meaning Medicine Men. Or, how some of us see the word meaning a get-together. The book holds traditional European magic spells, recipes, and folk remedies. These were used to cure simple domestic ailments and rural trouble. As to hex, hex work, or Speilwert symbols of pentagrams are thought to have talismanic properties. A pow-wow practitioner used the Sixth and Seventh Books of Moses. And, originally brought these books from Germany. The books contain cabalistic magic, which claims to have magic art by which Moses obtained his powers and commanded spirits. Another practice of pow-wow magic is the Himmelsbrief or "Heaven's Letter" and Teufelsbrief, a "devil's letter", which means to bestow a curse.
To me, personally, I believe hex signs are part of pow-wow magic. To say they are just "decorative" seems ridiculous.
Here's another book, written more recent. "Powwowing: A Persistent American Esoteric Tradition" by David W. Kriebel, Ph.D.