Final answer:
Jem and Scout's low opinion of Mrs. Dubose is due to her abrasive and derogatory behavior, which overshadows her internal struggles and moral courage that are revealed later in the novel.
Step-by-step explanation:
The reason for Jem and Scout's low opinion of Mrs. Dubose in To Kill a Mockingbird stems from their firsthand experiences with her abrasive nature and vitriolic comments, particularly towards their family and people of color in their community.
Her outward behavior is confrontational and derogatory, which deeply affects the children's perception of her, overshadowing any acknowledgment of her internal struggles or moral courage, which are revealed later on.Mrs. Dubose represents the entrenched racism and moral complexity of the American South during the time the novel is set.
As with several characters in the book, Harper Lee uses Mrs. Dubose to challenge the reader's initial perceptions and to demonstrate themes of empathy and understanding.