The Street- Final Passage

While I struggled with whether the central conflict in the novel was class, race, or both, Lutie's killing of Boots made me favor that race was the prevalent conflict in The Street. The passage that made this stick out to me most was on page 429, "Despite this unstable triple vision of him, she was scarcely aware of him as an individual. His name might have been Brown or Smith or Wilson. She might never have seen him before, might have known nothing about him. He happened to be within easy range at the moment he set off dangerous accumulation of rage that had been building in her for months." Furthermore, I was disappointed in the ending of the novel, and what the ending revealed about Lutie's character. While throughout the entirety of the novel I had seen Lutie as a strong women, not easily broke, working honestly to change her circumstances, by the end I disliked Lutie and found her to be more of a coward than any other character in the novel. I was disappointed to say the least. Thoughts?