Figure skating is not the only sport in which helmets in competition is frowned upon. For many years after safety helmets were introduced into riding, they were frowned on in high level shows as being too bulky. School shows everyone wore them, but at some point as you went up the levels in riding, you were expected to wear a soft helmet because it gave a better line.
As far as I know dressage competitors still don't wear helmets, just the top hat.
My opinion is that helmets in practice, especially when learning new stuff, is fine. But I can see the rationale, that if you are an elite competitive skater, you should be good enough that you can compete without one. If something is so dangerous that it requires a helmet even in competition, then it should be banned (like the detroiter).