I’ve often heard the response. “All Lives Matter,” when someone says, “Black Lives Matter.”
The best analogy I’ve heard is about cancer and disease. People wear pink ribbons and fundraise to show their support for the fight against breast cancer but no one says, “Hey, all cancers matter!” When Jerry Lewis did his muscular dystrophy fundraisers, people didn’t say, “Hey, all diseases matter!” If your response to Black Lives Matter is that All Lives Matter then it just seems insensitive to the people trying to bring attention/support to the disproportionate inequality some Blacks feel.
Much like you wouldn’t go to a breast cancer fundraiser and respond with all cancers matter, not just breast cancer. No one is claiming that all lives don’t matter or all other forms of cancer and disease don’t matter. Just this their way of bringing attention and trying to gather support for their particular issue.