^^^An example---despite Picard's version cited above, in Unity the Cooperative is composed of all the minds. The way the voices blend to make the usual Collective voice demonstrates that. The difference between the Cooperative and the Collective is that the members of the Cooperative spent time as individuals. Trek never showed a Borg planet. A similar situation could apply on every one of them, but the drones aboard a cube are no more typical of daily Borg life than a Starfleet member's daily routine resembles the ordinary Federation citizens'.
The Kazon may not be assimilated but they aren't being killed. The way the Kazon were written, this seems very generous of the Borg, doesn't it?

Also, given the confusion between assmilation and death, it is by no means clear that anyone is killed by the Borg other than in combat. There is no reason to think that combat deaths of civilians are a problem for any other posters here. Certainly, the vehement desire of the majority to exterminate all the Commies, er, Borg, shows no distinction between combatants and civilians in the Collective.
The Picard version may be all horror show but it makes no sense for a computer program to go to the trouble of suppressing organic minds to use the bodies. Robots would be much more sensible. The sentimental attachment to such nonsense is puzzling.
The Voyager episode Child's Play was directly inspired by the Elian Gonzalez case, with the Borg playing the role of Cuba. The episode cleverly condemned the mother for risking the boy's life yet still saving him from the evil Fidelistas, and fictionally kicking their asses for good measure. Oh, yes, the Collective was indeed usually a symbol of Communism. Beating the Cold War drums was one of the ways Berman Trek really was stick in the mud trash. But no one here complains about that.
Given the known intention for the Kazon to represent Bloods and Crips, i.e., Blacks, the wisecrack about not assimilating the Kazon had distinctly unpleasant overtones.