I comment on some of the videos I like but most often I dont comment, its usually due to not knowing what to say or I am in a rush after watching the video so I tend to just like them. I tend to leave comments for those I follow a lot like VlogRays and VahnChand, I watch most of their videos and comment on most of them.
I dont think anyone has the same amount of comments as views if that is what you mean, there will be some videos with say like 3 comments and 3 views but really its rather rare when it gets into bigger numbers.