Sure, once you're cornered on the issue.
And I noticed you didn't say anything against drowning kittens or whipping horses . . .
Probably for the same reason the Salvation Army doesn't speak out against poaching elephants or St. Jude doesn't raise funds to save the rainforests: because
those aren't the issues their organization was created to address.
On the other hand, I'm sure if you sent an email to the chair of Blue Lives Matter asking him where his org stands on discriminatory policing and racial profiling, he'd probably tell you he was against them.