Black Live Matter/All Lives Matter

I head a really good explanation as to why the retort of some people to the phrase "Black Lives Matter", which makes some non-black people uncomfortable, should not be "All Lives Matter".

Imagine a person wearing a "save the whales" t-shirt. Someone sees it and says no, "save the animals". Such a reaction is non-nonsensical.  The issue I think is that non-black people are not a third party such as whales so they misconstrue the statement "Black Lives Matter" to be "Black Lives Matter More" which is just nonsense.

I am heartened to see many white people here in Minnesota wearing "Black Lives Matter" t-shirts. If we ensure justice for black people, which I believe can only be accomplished through true legal reform,  it will help ensure justice for all. Maybe even me. Yes, black lives do matter.