I discovered highly interesting aspects when I followed up the 'controversies' link given with niggard. Usage (in various spellings)is richly illustrated in the Oxford English Dictionary with examples going back several centuries. The irony is that the doubling of the letter 'g' had taken place centuries before, and in a decidedly 'free-for-all' climate, before a quirk of orthography doubled the 'g' in a taboo word derived from negro. I have to remind myself that much of the meaning of a word often lies in the way it is used or misunderstood, or in the inferences drawn by the hearer.