Pay attention. They protest even when armed blacks are killed.
BLM is the boy who cried wolf. When you keep making an issue of the cases where the police did nothing wrong the real issues like George Floyd get lost in the noise.
First, no one knows right off whether anyone did anything "wrong". I realize that many people automatically take the word of the police without corroboration, but without people making "an issue" out of the case, there would be little or no corroboration in many instances.
Second, your standard for "police doing nothing wrong" is different than many other people's standard.
Third, it seems what neither you nor most of the kneejerk supporters of the police seem to grasp is that the police in general have lost the trust of a significant portion of the population. Until the police regain that trust, the distrust and cynicism about their actions and motives will continue.