It is disabled to make sure you shop for a home entertainment package, nothing more.
The funny thing is that putting up obstacles like this is just forcing people to find workarounds. I like using aDownloader, free from the market. Paired with MX Video Player or BSPlayer lite, I get everything free and it works over hdmi.
If you have HBO at home then I would say that you are within your rights to view shows however you like, but I'm no lawyer. Just move the video files out of bittorrent after they've downloaded so that you stop sharing them with others.