I think this article hints at what may have been one of the causes of that change in direction. It appears that Russia faked black radical activism in social media in order to intentionally sow division in the US. But that action plays into the larger current political climate where it's "either you're with us or against us" by default rather than "even if we don't agree on everything, let's make progress where we do agree."

The same people that say "all lives matter" would be saying "You're undermining our cops therefore putting them in danger. You're literally getting cops killed."

The reason why the "all lives matter" people exist isn't because they're honestly misinterpreting the "black lives matter" message. They're dishonestly misinterpreting it. If you worded it differently they would find a different way to dishonestly misinterpret it.

Maybe. Maybe not.

I think there's a middle ground.

https://www.youtube.com/watch?v