It might be but often it's not. A common reason comments are disabled is that a female is in it which invites rude sexist remarks. For example, there was some advanced math university lectures taught by female professors and every one of them was spammed with "men of culture, we meet here again". Understandably, the channel later disabled the comments out of respect for those women but at least the dislike numbers were still visible.

>, it is still very easy to discern whether the video you are about to watch is controversial.

No, it's actually cumbersome and wastes extra time to determine if many how-to videos are bad quality without a dislike count. That's why so many are irritated that Youtube removed it.