Respectfully, it seems clear because you're living under a siege mentality. "All Lives Matter" is a short phrase composed of common English words - some people do use it as a slogan to oppose the BLM movement, but others use it as a compact expression of the idea that every human's life has value. When Jennifer Lopez tweeted "#AllLivesMatter #LoveMakeTheWorldGoRound" over a picture of herself holding hands with Lin-Manuel Miranda and rainbow flags waving in the foreground, is it really plausible that she was declaring her allegiance to anti-BLM groups?