The reason people care so much about this issue is that many of us feel it shows that the current method of applying the rule of law produces bad and immoral consequences. Yes, it is true that Mr. Swartz's previous writings may establish intent in a way that is relevant to criminal prosecution. It is also true - and I believe an ultimately more significant matter - that this case demonstrates that "writing about what you believe" may indeed place you in greater criminal jeopardy, and that consequence of the "rule of law" as it was enforced in this case may cause more harm to society than the "evils" the laws were intended to prevent.
In other words, the significance of this case is that it shows our current methods of applying the laws may have negative consequences. Saying "the prosecution was applying the law correctly" is not relevant to the question: does this case show that we should change the laws, and how they are applied?