Here's why: most of us like the product Hollywood puts out. But we hate the way it's distributed to us. (For instance, this article's rant about loving "Gladiator" but hating the way it was exhibited in one case). By pirating the material, we end up hurting the creators just as much as we hurt the distributors. So everyone loses.
Piracy will always be around, because it's really easy, and the genie is out of the bottle. At the same time, I believe that people will gladly pay for better distribution strategies. Witness the rise of Netflix and iTunes.