I agree. A comment is better than a like, but in my case knowing the age and sex of the liker or disliker would tell me if am appeasing my target demographic. For example, my channel is a "Mans" channel. I target adult males between the ages of 25 and 50. Analytic says that 85% of my traffic falls in this range. I have about 6% women of all ages and 9% of males of ages outside my target demographic. I have about a 10% dislike ratio. That seems high but if those dislikes are predominately from women and kids, then it does not matter because my videos were not made for them to like anyways, and it is perfectly normal for them to not like them. So being able to see dislike ratios in conjunction with demographics, would really be useful to me.