You omitted those who consider that there are different forms of socialism. Bertrand Russell covers this ground in "The Practice and Theory of Bolshevism" (whic

You omitted those who consider that there are different forms of socialism. Bertrand Russell covers this ground in "The Practice and Theory of Bolshevism" (which you'll find on Project Gutenberg). Since he was writing in the 1920s I don't think it can be considered too revisionist.