She's not showing genuine concern at all. She's trying to divert attention away from racism by saying oh but look, members of the African- American community do this....to each other so let's look at that.
It's exactly the same as when there's a post about female victims of domestic violence and someone comes on and says but women are violent too and to their partners.
People of lower socio - economic status have increased rates of violence. Because they live in a society where they have poor housing, poor access to education, health care, higher rates of neglect and abuse in childhood, increased rates of parental drug use and criminality, increased rates of drug use and criminality in adulthood, increased rates of severe mental illness and incarceration in prison or secure MH facilities.
And African American and Black British people are always as a group over - represented in low socio - economic groups so experiencing more of these problems than White American or White British people.
So the wide eyed 'oh look at all the blacks killing blacks' (I object to that language as I have previously said) is a faux concern and ignoring the fact that there are higher rates of violence in lower socio - economic groups BECAUSE they are a lower socio - economic group. And the reason they are a lower socio- economic group for people of colour is because of centuries of racism.
That's why people get really annoyed by these threads. Because anyone with any sense or knowledge of these issues understands this. And it's frustrating that other people are so ignorant.
And it does of course also have implications of further racism - that posters don't want to say it outright as it would completely out them as racists but they are suggesting that there is an issue of violence specific to am ethnic group because that ethnic group may be inherently more violent.