tl;dr - We didn't think about your comment. We assumed you were taking a side. You didn't spell it out for us. We didn't bother to find an interpretation that would make sense.
tl;dr^2 - We are lazy and have poor reading comprehension.
I'm very sorry, if it taxes your imagination that someone would want to talk about what was written on the button. It's not like that would be at all relevant to the article, I guess. (My apologies to the sarcasm impaired.)
When communicating, it is our responsibility to express our thoughts as clearly as possible. Dashing off vaguely worded comments and then insulting the reader when he seeks clarification is not a generally accepted practice in the field of writing.
To explain the confusion better: You say you "referred directly to the button's content," but you didn't. You referred to it obliquely. The grammatical subject of your comment was "this sentiment." That is as specific as you got. The most obvious antecedent is "the sentiment expressed in this article" — which is what people assumed. In order to get your true meaning, the reader has to actually ignore the grammatical structure of your comment and read in a subject which you didn't explicitly mention anywhere and which is actually off-topic for the current discussion (people will generally use the overall topic as context when trying to determine the meaning of ambiguous phrases).
At any rate, insulting people who are confused by imprecise wording is kind of rude.
As for the button's actual content: I think you're taking the jokey posturing too seriously. As he explained in the OP, the reason he liked the phrase is because it reflects an actual divide between the two cultures — almost any fantasy fan will have read Tolkien, whereas many (probably most) sci-fi fans are focused on present series and haven't read, say, Heinlein. Depending on your school of thought, it could be making fun of fantasy fans for being stuck in the past or it could be making fun of sci-fi fans for being ignorant of their own.
It's one of at least two reasonable explanations, while the context favors the other. For effective communication you need to consider how the other hears what you are saying.
On a more general note: you are often terse to the point of becoming cryptic. Removing ambiguities and room for interpretation are also effective usages of language. Merely expressing an idea in the shortest possible way is often not as effective in communicating the idea.
tl;dr^2 - We are lazy and have poor reading comprehension.
I'm very sorry, if it taxes your imagination that someone would want to talk about what was written on the button. It's not like that would be at all relevant to the article, I guess. (My apologies to the sarcasm impaired.)