YouTube is experimenting with hiding dislikes. The update is expected in April.
The statistics will be visible on YouTube Studio.
Thus, the site will fight against "dislike mobs". Now the user will not see the number of downvoting with the video, but he will still be able to put a dislike - this will affect personal recommendations.
In the current setup, stats for both likes and dislikes are viewable in a creator’s individual YouTube Studio page.
In a support article explaining the test, YouTube says that dislikes can negatively impact a creator’s well-being and “may motivate a targeted campaign of dislikes on a creator’s video.” Basically, the idea is that seeing a dislike number and watching it go up could be enough motivation to join in and make the number larger.