All right, let's go into specifics here.
I strongly disagree with your description of the objectionable comment:
* First, saying that it is "non-offensive" to compare someone to Stalin's regime (or more generally to the Soviet regimes) is so blatantly inaccurate that it's difficult to believe that you seriously advanced that claim. Let's set aside "offensive" and say merely that comparing someone to Stalin is in virtually all contexts likely to be inflammatory, perceived as aggressive and hostile, and very likely to derail the discussion. It is not innocuous. So the original claim, with its comparison to Stalin, is immediately suspect because the author has chosen a way to express their disagreement that leads the conversation away from substance.
* When you say it "draws an analogy between two organizations which used propaganda effectively" you elide important points of information. For one, the nature of any comparison to Stalin. For another, the comment did not, I would say, "draw an analogy," it proposed one - and then took it for granted that the analogy was sound and useful. It presented no evidence for this point, it just stated its view as a _fait accompli._ That is not a good way to make an argument. When you advance a position, you're also obliged to advance evidence for it if you want it to be taken seriously. Humor is no defense here: the commenter was using sarcastic humor to advance an argument, and is not excused from the requirement of presenting evidence for the argument.
* On your own part, when you say "Comparing Mr. Gruber's writings to those of fellow travelers..." you too are assuming facts not in evidence. Do you mean that Mr. Gruber is a Stalinist? Then please advance the evidence in favor of that, or abandon your argument. You are obliged to present your arguments and their evidence forthrightly, not to wink knowingly and wave in the general direction of something faintly evidence-like.
* That the comment "places the article within a larger historical context" is so low a standard as to be useless. Any comment here that referred to events outside of 2012 could be said to do as much. Even if the above critiques did not hold, saying that the comment added "historical context" would be too glib, would not be a substantial point in its favor. If the comment were presenting evidence for its views, that would be one thing, but to say that the comment as it stands adds "historical context" is to say nothing, because by that standard you could defend the legions of facile "Apple would never have done X while Steve Jobs was alive" comments.
* The comment advanced, more or less, the argument "Apple's press releases are a form of propaganda; their terseness requires us all to make inferences and guesses about goings-on inside the company that do not serve our understanding well." This is a mere argument - which is a good thing! It is something that we can have a discussion about, reason about, and it is capable of being falsified. For that matter, if the comment had had what I just said appended to its original content, then all would have been forgiven. But instead we got only the version of the comment that flatters the prejudices of people who are already convinced that Apple is a bunch of no-goodniks and which has nothing useful to say to people who are not already convinced of its argument.
In summary, I objected to the comment because it advanced its argument by a method that was obviously likely to drag the discussion in unproductive directions, because it advanced its argument without presenting any evidence, and because it was advancing by insult an argument that could have been advanced without the insult just as productively. I disagree with your defense of it because you are neither holding it to a high standard of argument nor addressing any of its flaws - flaws which are obvious enough that my listing them is barely necessary.
Now, since you spoke up to defend it, you have heard its measure. It didn't add anything to the discussion, and the comparison it made was not helpful to anyone's understanding of the situation. I'm willing to put effort into explaining exactly why I think that because I think that a high standard for discussions here is important and necessary, and that letting comments like the one I object to slide by without expressing that they do not meet those standards, is part of maintaining that standard of discussion. Silence on community standards serves no one well. When objectionable comments are met with vigorous resistance, it not only shows the people making them "no, that kind of comment is not welcome," it affirms the community standards by setting them out explicitly and bringing them to everyone's mind. This is why I'm willing to write this much telling you and the author of the objectionable comment why I object. It is not about my disagreeing. Disagreement is a normal part of discourse - but there is no productive disagreement to be had unless people make their arguments plainly, make them falsifiable, and make them by going from evidence to conclusion.