[mikeash]

By that measure, no political organization can be considered completely peaceful and nice, making it meaningless to say so about communism.

(Excluding full-on no-government libertarians from the above under the assumption that organizing would be contrary to their beliefs.)

[davidhollander]

Yes, that was my argument. I believe it stands until a semantic context for "completely peaceful and nice" can be proposed that is disjoint in meaning from "nonviolent and voluntary".