Black and blue lives matter because all lives matter (and that universal ideal should be reflected in our society).

Should be but it isn't, ergo: Black Lives Matter... BECAUSE it seems like in the past 20 years (and further) that they haven't, really.

Of course, but it would be incredibly naive to expect white supremacists to use "all lives matter" honestly.

Right, but the point is by saying All Lives Matter, at least in my opinion and I'm sure that of many others, you are tacitly saying, "I believe every life matters equally and if any don't then we need to fix that." while avoiding the now-too-politicized phrase Black Lives Matter.

Your sentence didn't make much sense as you were trying to draw a point, but then carried off into what we were saying.

The problem with ALM, is that it's too often used as a way to silence the plight of the Black community. Saying "Everyone has problems. Deal with it." That's the issue people have with it and that's how the message has been used. Both slogans have been sabotaged with bad faith arguments. Best stick to the original message that was intended.

The message that I said, "I believe every life matters equally and if any don't then we need to fix that." is literally what Black Lives Matter is about.

Then let's part ways with the mutual understanding that when you say Black Lives Matter you are specifically calling out injustice the black community has faced and when I say All Lives Matter I am calling for everyone to affirm the ideal that everyone has equal dignity and to make affirmative change (if need be) so their lives reflect that ideal.

Actually I think the BLM movement leaders care little about any lives, including black people.
BLM has not said anything about the large scale slaughter of Nigerian Christians.
Mothers who lost loved ones to police have come out accusing BLM of what I am. Look up Samaria Rice.
And what the hell is up with BLM criticizing people of protesting against their communist regime in Cuba? They even praise the dictator!
No, I really don't think they care about anyone. The good people like you who have hopped on the bandwagon do care but the BLM leaders and management has tarnished any merit the group may have achieved. Until new management occurs, until past wrongs are righted, I will remain steadfast in my stance regarding them.