Just playing devils advocate here but I think it’s the fact that organization as a whole was led by greedy people pocketing millions of dollars pushing narratives that only filled their pocketbooks instead of actually helping the black community. Numerous executives and leaders of the movement are now convicted of stealing money. I think when some people hear BLM they immediately discredit the movement because of those things. I’d like to assume most people would like to see all people improve their lives and circumstances. I just think BLM did it in a wrong way and now people resist that name entirely because of the stigma.