I think unorthodox goes beyond the 'idiosyncratic movement' and more into the realm of very different from the norm. Furyk's swing is unorthodox because just don't see many people with that type of swing. Adam Scott? There are a lot of players with similar swings. In fact, Scott has been accused of copying Tiger's swing during the butch Harmon years.
I don't find anythign unusual or daring about calling Fowler's swing unorthodox because it is unorthodox. I think a lot of this is just the fear of people interpreting unorthodox as being 'wrong' or 'bad.' It's not that either.
I treat 'unorthodox' as something that most people cannot do consistently. and if they are having trouble with their swing, one needs to figure out if the unorthodox parts are causing them trouble. If so...fix it. If not...find the real culprit.
It's easy to see why people get brainwashed into thinking unorthodox = bad because that's the general way 'method' instructors teach. Something differs from what they interpret as orthodox, they change it regardless if it is causing the problems or not.
Having a 'model' can be useful in helping improve golfers. It just depends on how the teacher uses the model.
3JACK