The very few incidents of left-wing people attacking/killing others are not planned, premeditated, organized things like the attack on the U.S. capitol. No left-wing people are showing up to marches with zip ties planning to kidnap politicians. No left-wing people are planting pipe bombs at political offices. No left-wing groups are trying to infiltrate the police to...demand police reform or make them stop killing minorities? Shit maybe they should. Much better than right-wing groups infiltrating them to hopefully incite a race war.
If you can't tell the difference between people protesting police brutality and the police targeting of minority groups, and people storming U.S. state capitols and the federal capitol with guns, trucks full of bombs, zip ties, etc., as part of a planned action, then this discussion is pointless.
American cities burned, people were killed and beaten, property destroyed for the last 7 months now. How is that decades ago. I can't even understand why would you even try to whitewash any kind of such primitive violence.