It's actually not harmless because it undermines geographically exclusive distribution licenses. European distributiors pay a lot of money for the rights to sell Hollywood movies in Europe and are understandably annoyed when people then import movies from the USA and watch them with crowdsourced subtitles.
Arguably, the benefit to consumers should outweigh the harm to license models, but that's not what the law says, currently.
And I did not say that it wasn't. Nor did I say if the law is just or not, but simply clarifying that transcribing/translating movie dialog is breaking copyright law.