Is it rude or disrespectful to argue/debate with elderly people?

Based on a conversation I had with someone recently, who believes it’s disrespectful to argue or debate with an elderly person. The conversation was sparked by an elderly family member who grew up during racial segregation and said they think it would be better if people segregated again because “as much time that has passed, white and black folks clearly just can’t get along.” I told the friend I would have debated the issue with her, but she said she felt it would have been rude, considering the person’s age.

Do you think some issues are better left alone with elderly individuals because they’re so set in their ways and beliefs? Or regardless of age, should they be challenged if they say something you disagree with?