I think it's because of the tags as well as false claims in the youtube video being 'original' basically attracting a ton of viewers...and soon getting a 1/10 like ratio, one like for every 10 dislikes, however, Youtube's system doesn't give a shit about likes, only views and how long the people stick around, which is why you see longwinded intros to these 'reaction' vids. Pretty clever, honestly.