When they stood with Boston after the marathon bombing, the slogan "Boston Strong" was okay with virtually everyone. You did not hear people in Houston complaining that they were strong also.
Same with Las Vegas after the concert shooting. Social media largely replaced the slogan about "what happens in Vegas" with [hashtag]VegasStrong. None of that is insulting to other cities.
If people raise money and awareness for death-dealing strokes, it doesn't mean those people are for death by cancer.
A group has a specific cause about black lives and some of you act as if they are against blue lives or white lives. Not at all. It's really no different from people fighting to save the whales and you all assume they wish porpoises would be killed.