Legal DVDs have limited selection of subtitles and you can not rewind them 10 seconds back to review scene if I misunderstood. I downloaded even movies I own for that reason (downloading is legal here, uploading is not). I like to watch movies with english subtitles an dvd rarely have those.

I do not care about extras. I do care about ability to jump where I want in the movie and about seeing movie I brought without warnings and ads.