I'm not sure this follows. I'm guessing that Hollywood sees piracy and filesharing as vast amounts of unrealized profit for the work they're already doing -- "free money" essentially.
I think it's personal too; look how bent out of shape Scott Rudin got just because David Denby published a review for "The Girl with the Dragon Tattoo" a week ahead of a previously-agreed-upon embargo: http://www.guardian.co.uk/film/2011/dec/05/girl-dragon-tatto...
Hollywood seems to like having control over when and how their material is released, and on this level piracy offends them on a moral level.