"Racism" by definition involves having power over others.
Black Lives Matter was born out of frustration and outrage at the ongoing, systematic brutality, unpunished killing, and other shameful treatment of black people, particularly black men/youth. These actions have been widespread, deeply rooted in institutions, not just individuals. History speaks for itself in our shameful history of racism as a country: power and domination over others justified by an invention of "race" as a difference in the human family.
Now, with more video and social media, it is much harder to deny what is going on in our country with regard to frequent police brutality and assassinations. These are only the most dramatic examples of how racism is hurting us.
As a white person, I don't have to be vigilant about how white people see me (as a threat, as uppity, etc.). I don't have to wonder if I'm welcome in a neighborhood or if I'll be watched in a store, or even walking through a neighborhood. I didn't have to prepare my child to deal with racial slurs at a young age, or fear for her well-being.
I have a family member who is a police officer, and we have discussed this topic. She is committed to being on the right side of things.
Black Lives Matter is not "racist" because black folks do not have institutional power in this country. It is a response to racism. In my mind it is saying, "We count." I celebrate the movement as something that can benefit the future of our country and to fairness for all people. That would be truly great.