Muggles are non-Harry Potter fans. Ignoramouses.
Some HP fan knitters used the term here & there. I just read a bunch of blog comments about elitists using “muggle”–comments from real Muggles.
If you don’t understand Harry Potter, you’re not going to understand how people are using “muggles” in terms of knitting–plain and simple.
It’s not an elitist thing. It’s just geeky. 🙂