The obvious purpose of these "white lives matter" and "all lives matter" memes was to distract from the "black lives matter" campaign/movement as if to say that equality negates the legitimacy of highlighting the continuing struggles of a group that has been historically ill-treated and continues to face discrimination. However, we can agree with the "white lives matter" and "all lives matter" statements.

The "black lives matter" slogan is based in the idea that people in America have been treated as if their lives didn't matter, because they were black. People in America were not treated as if their lives didn't matter due to being white, so no such a slogan would be necessary for any such a reason.

"White lives matter" is trolling, basically.