I think the wording “discredit” is not correct in this case. I don’t wanna discuss the whole Russian revolution analysis by Luxemburg, which she wrote in prison btw. But when I read the latter and also her works I always saw her as a critical friend. She was a Marxist and a Socialist and she would only formulate her critique from a place of admiration and sincere conviction. Her critique is never not out of a Marxist perspective.