I partially understand the motive here; I guess that only under one percent of these "fansubs" are used with legitimately downloaded video material (never heard of this happening) and the availability and ease of use of the subtitles makes it more tempting to get videos from "pirate" sources. But is it actually a crime to transcribe a movie's dialogue with time codes and share it and is the situation similar to lyrics web sites?
Transcribing subtitles and diffusing is exactly like transcribing lyrics and diffusing them: making a derivative work and spreading it without permission infringes on the copyright of the song/movie the transcription was based on.
If it’s considered a crime or an offence depends on the scale and context of the infringement and probably on the country that you’re in.
A subtitle file is pretty useless without a video file or disc. Transcribed lyrics, however, can be enjoyed on their own, without having access to the music.
I partially understand it, but I can't accept it as long as I'm unable to get the media I want with the subtitles I want.
I'm perfectly willing to pay, but all too often I simply can't.