I'm sure you have an idea of why by now but even so, read this great summary in Scientific American, on how Hollywood is promoting online piracy.
Basically it comes down to protecting their existing "disc delivery system". This term may sound somewhat unfamiliar but I'll walk you through it.
If you have ever seen the great movie "The Insider" with Al Pachino playing the role of a CBS 60 Minutes producer and Russel Crowe the tobacco industry whistle blower, you may have an idea what I'm talking about.
The Russel Crowe character (Jeffery Wigand) is explaining in the movie how the cigarette is merely a "A delivery device for nicotine". The cigarette itself has no function but to deliver a drug as efficiently as possible and to make the user as dependent as possible.
If you apply similar reasoning to understand the actions of the entertainment industry over the past decade it becomes quite clear that content (music, movies, TV-shows etc) is a delivery device for discs (CD, DVD & BluRay).
Since the day it was possible to store recordings of music, TV and movies, the entertainment industry has really been a logistical supply chain for physical media. The airing of TV-shows, concert performances by musicians and movie viewings is merely advertising (but often profitable) for the following disc releases.
To the entertainment industry it doesn't really matter what is on the discs (I think we have all suspected this from time to time after digesting some especially crappy movie, music act etc), as long as they are shipped far and wide and make as much money as possible.
With this kind of mindset in the industry, it is no wonder that they have tried to shut down legal online alternatives, driving users to piracy. If it would have been about the content, then the internet would have been a new and possible extremely lucrative channel. At the moment it is a lethal threat to the core business, shipping discs.