People who say Black History must never be discussed, for fear of hurting white people's feelings are clearly a bit unhinged / fragile; the famous 'white fragility'
However, I think it is a bit more nuanced than that.
I think there has been a level of mild pushback from people who generally agree with the BLM movement, but who also don't believe that debate has to be shut down at every turn by shrieks of "white privilege". When I saw the message go from "black lives matter" to "white lives do not matter", (that is a verbatim quote), for example, which was a conversation I saw play out on instagram recently, I did question whether I could get on board with that. No, I can't. But it got a lot of support on there. I think I have educated myself and continue to do so, but there are still comments I don't think are quite right. Another one which jumped out at me was; "after the revolution, white people should not be permitted to hold jobs which put them in a position of authority, because they are white and cannot be trusted to hold those roles". This was an argument made by a popular IG influencer and campaigner for black rights in America. Again, I don't agree.
I wouldn't wade into BLM online spaces and tell them they are wrong, but I reserve the right to privately think these particular arguments are bullshit, even having read carefully what the people making the arguments have written.
The comparison to cancer..."it's like saying you can't campaign for pancreatic cancer awareness without campaigning for other cancers". Yes, completely right. BUT, when it is more like..."I'm campaigning for pancreatic cancer, because all you other cancer patients are giving me this cancer and I think you probably shouldn't be able to access treatment for that cancer, because of the history of you cancer patients' ancestors oppressing pancreatic cancer patients means your lives don't matter"...the analogy is less poignant iyswim. So, as I say, I think it is a little more nuanced.
The other thing is, people who identify as POC in america, include people of European spanish heritage. There is some confusion as to what a POC actually is, as in the UK, we would probably call someone of European spanish heritage white. In America they would be Hispanic, I believe, (but not Latinx).
FWIW, I'm white; Irish Catholic. Feel I should declare this!