It's funny how differently people react to things. I look at this and think "there is nothing about Youtube that I find more useless than the dislike count, and I think this probably - on balance - a Good Thing." Everybody else seems to think it's an attack on the fundamental essence of all that is Right, Good, and Just in our universe. Weird... I never would have expected so much consternation about a dislike count.
If you read the comments in detail you will see that people describe how they used the dislike count. It's therefore not useless.