Yes, any speech calling for violence is not helpful and I think worthy of discussion about the effects it has on our society.
Groups can practice boycotts, peaceful protests, civil disobedience, political activism, fundraising, etc. without resorting to violent speech.
How do you feel about certain protestors being called terrorists?
People openly call for violence every day. People vote for it, it's what they want. Just look at the wars in the Middle East. Entire nations are calling for that violence.
Right now, society has the belief that violence by the state against people is sometimes justified, but never the reverse. Unless it's against a 'bad' state, then it's okay. Then they're freedom fighters.
You mean like 'no justice no peace' or just speech that doesn't align with your political ideology? (To be clear, I'm all in favor of defunding police and the government at large)