Mispellings. Mispronunciations. Miscommunications... misinterpretations... mis... mistrust. And misery. All to misery.
Madness string 27
In essence, the problem is that, if it walks like a duck and quacks like a duck, it could be a dragon doing a duck impersonation. One may not always want to let dragons into a pond, even if they can impersonate a duck.