The stated reason for getting rid of dislike visibility was very suspicious to me. While I don't deny that targeted harassment and bandwagoning with dislikes on certain channels/videos happens, there's no way it was happening frequently enough to warrant removing the feature from all videos. I saw no reason why individual creators couldn't stick with hiding the controls on a per-video or per-channel basis.

Removing the dislike count takes away a valuable indicator of low quality and/or time wasting videos. Yes, it has false positives on charged topics, but I use it to help determine if an intriguing recommendation or search result is actually worthwhile or just clickbait. I suspect YouTube was pleased to remove the like/dislike visibility because it would boost engagement metrics. I assume any concerns about quality or the viewing experience are secondary or considered inconsequential.

Edit: They removed the dislike visibility, not the dislike button.