Leninism (and Trotskyism and Stalinism, depending on which side of the Stalinist/Trotskyist divide you fall on as to which one was simply fidelity to Leninism and which one was a substantial revision that unfairly characterized the other) and Maoism were not scientific revisions of Marxism; that is, they were not a result of Marxism being a hypothesis that was empirically tested, failed, and alternative hypothesis whih better fit the available evidence being offered and tested.
My understanding is that ML and MLM _were_ considered to be legitimate, scientific advancements, and that's why it's just M, ML, and MLM, and why Trotskyism/Stalinism/Hoaxianism/Luxemburgism don't get the full-on status that the top three too. That said, I am not as educated on the topic as I would like to be.
Also, let me just say that I never expected to read a post like yours or type a post like mine into an HN comment box, kudos.
