Rubashov is a figure who represents the Old Guard of the Bolsheviks, those who were regarded as having had "pure" motives in the Russian Revolution of 1917. As such he is a hero to those who believed in the principles of the Revolution and its championing of the working class....
Rubashov is a figure who represents the Old Guard of the Bolsheviks, those who were regarded as having had "pure" motives in the Russian Revolution of 1917. As such he is a hero to those who believed in the principles of the Revolution and its championing of the working class. During the actual purge trials of the late 1930's under Stalin, it was a shock to people on the left that many of these Old Guard members were arrested, forced to sign false confessions, and executed. Many of their admirers regarded them as weak for folding under duress and admitting to crimes they had never committed. Or conversely, those who believed the confessions became obviously disillusioned with men who had been regarded as heroes to the cause of Communism. The quote in your question expresses the first of these views: that Rubashov should not have caved in and admitted he was guilty of what were essentially false charges.
The ambiguity in the case of Rubashov is that he himself no longer believes in the cause of the Revolution. In reviewing his own past, he sees that although he may have been loyal to the Party in a strict sense (and that he's therefore not guilty of the charges), his own behavior has been self-serving and amoral. He has betrayed Party operatives like the young man in Germany who was simply attempting to serve the Party in the way he thought best. And Rubashov realizes that the Party itself, under "Number One" (a code name for Stalin) has become corrupt, that it no longer represents the people and has become a totalitarian organ no different from the Nazis in Germany.
Yet Rubashov, in recognizing this, has redeemed himself in some sense. At the close of the story the last thing he hears, before he is shot from behind, is the other prisoners rapping on the walls and shouting their solidarity with him. And an ordinary working man like the porter Vassily still defends Rubashov as Vassily's daughter reads to him the news account of Rubashov's trial.