Thank you for your posts, HannahYeah 
I was going to say that the BLM movement would probably have come up against far less opposition and the whole "All lives matter" thing if they'd only added a "too" on the end - but there is a reason they didn't and I can't remember exactly what it is, which is to my shame.
The "All lives matter" is pretty much exactly the same as when people say "what about the men" when women are discussing domestic violence against women, or rape. Women far outnumber men, by a huge proportion, in being attacked by a domestic abuser or rapist - and yet there are still people who can't stand the idea that men could possibly be left out. That is male privilege. We, as white people, may not understand white privilege (or like the term - personally I think it's apt) but MOST of us should understand or have experienced male privilege from the wrong side. SO why is this so much harder to understand?
Answer: it shouldn't be.
And to whomever it was who said that President Obama didn't stamp out racism in America - well no. But then neither did Margaret Thatcher stamp out sexism in the UK.
As women, we can work our arses off to be equal with men in the working world, the power stakes, whatever - and still be second best. Because of our sex.
But we're not likely to get pulled over or shot by police because we're women (and that's where THIS analogy falls down completely) - unless we're also black.
A black female state attorney was pulled over in Orlando by police on pretty spurious grounds. When she handed over her ID and told them she was a state attorney, they backed off - but the reason they pulled her over in the first place was because she was a black woman in a fancy car (not that that is what they said, of course!). Wouldn't happen to a white woman, nor a white man.
There are good and bad people of all races, colours, religions, whatever. And MN is not a homogenous mass either, so to call MN racist is not correct - there ARE some very racist people on MN, but there is a huge number of different people on MN and they are not all the same.
The analogy at the top is as good as the house burning analogy but I agree with the poster who says that it's not good enough because it starts from the incorrect premise of all people being perceived as equal, which they are not. No good reason for it apart from white supremacy feelings.