I guess I look at it from the standpoint that if you take the same word, and have it pronounced by someone from Boston, someone from Appalachia, someone from the Midwest, a Cajun from Louisiana, someone from Texas, and someone from southern Georgia, you are going to hear six different pronunciations, all of which will be correct for the speaker. That does not include the way it might be pronounced in various areas of Great Britain, Scotland, or Ireland.