I feel the same way (concerned about my prejudice) and added to that is I tend to pick up the accent of people I'm talking to. I have lived and worked in the south. I grew up with another accent that sounds ignorant: Da Yooper, eh?. I think we accept it when we are living in it and interact on a daily basis. It takes time, though. The Midwest Siri:
https://m.youtube.com/watch?v=l_8n2q5iI4E