I've often wondered the same thing myself.

Still, mere difficulty of text in Aristotle or any other philosopher could be irrelevant to the question of whether he can speak to us, and do it in a way to make us sit up and take serious philosophical notice. The current philosophical scene is dominated by two figures, Martin Heidegger and Ludgwig Wittgenstein. Consider the experience in store for anyone who chances to take a first look at a page in the work of either one. "Gibberish, and pompous gibberish at that!" one might well blurt out at first reading of a page of Heidegger. As for Wittgenstein, what he says is not apparent gibberish, but one might still be utterly baffled, not so much as to what he was saying, but rather as to what possible point there might be in his or in anyone else's ever saying it. Yet such difficulties have not deterred thousands upon thousands of students in Germany, England and America from rushing after one or the other of these two latter-day philosophical piedpipers. What's more, they will spend hours and days and weeks puzzling over what Heidegger could have meant in this passage, or Wittgenstein in that. To a cynic, indeed, it might almost seem as if any truly living and vibrant philosophy must thrive directly in proportion to the opacity and even perversity of the texts in which it is written.

Edward B. Veatch, Aristotle: A Contemporary Appreciation, 1974.