Saving movies to disk makes a lot of sense - I like not having to rely on either a big company's services or library nor some sketchy, slow illegal streaming site. Not to mention a vast number of movies are not available for streaming illegally or legally in a convenient way.
If I download a movie I know it will always be available and work 100% of the time regardless of internet connection or money. If I delete it after watching, BitTorrent gives me a similar guarantee provided I can be online.
I don't use streaming, and it's interesting how when I go to someone else's house, I'll be like "It should be on Netflix" and it's not .. but it was a few years ago.
I recently met up with an old roommate who still keeps a NAS with TV shows and movies and he had tons and tons of stuff on there that you simply can't find anywhere. Lot's of old kids shows for his daughter, old stuff that you could only get on MySpleen.
With everyone moving to streaming and not having the wall of DVDs/BluRays/VHS tapes, we have lost something, but stuff isn't on streaming forever. Things rotate out, and fewer people are actually buying media. Even with eBooks, you're paying for a license to see that media for a limited use.
If I download a movie I know it will always be available and work 100% of the time regardless of internet connection or money. If I delete it after watching, BitTorrent gives me a similar guarantee provided I can be online.