(asked by Red from Chicago but currently in Paris)
What’s wrong with scarves? I’m not sure I really understand your question, are you asking why do French people wear scarves in Winter?
Well, the simple answer is to keep warm in the neck area and to not catch pneunomia or similar unpleasant sickness caused by cold and humidity.
So, sure in Paris it’s also more than a practical piece of clothing and it is also a fashion accessory. And it makes sense as it’s cold about 10 months a year in Paris, so one tends to wear scarves more than in other places in France or the world that have a decent climate.
Now, I’m not sure what you mean about scarves and the US, but during my time in the US, I lived a couple of years in a quite cold region, and believe me, everybody wore scarves in the Winter.