YouTube inserting itself into the creative process in an unwanted way is a violation of something that was previously personal and private. The artistic choices a video creator makes are their own, changing them changes the meaning of what they created and violates the authentic connection between the artist and the audience. Imagine if the comments you made on videos were edited to be something else -it's a violation of our ability to even express ourselves in public. A private decision making process is being taken away from artists.
This isn't unrelated to privacy.