That is not a safe assumption at all. You're assuming the total number of votes is proportional to the view count. But a more provocative video will prompt more people to vote
A video that makes people angry might encourage people to vote who otherwise wouldn't have voted
I think a popular video will attract votes one way or the other.
A video that makes people angry will encourage people to dislike the video, and thus eat into the total vote share.
I agree that this likely only covers videos with a large number of views (~millions). There's a long tail where the view count/vote count is not enough to comment on the number of dislikes.
A video that makes people angry might encourage people to vote who otherwise wouldn't have voted