Why do the most recent comments on Youtube have the most thumbs up?

It's at the top because it is the highest rated comment and not because it is the most recent.The comments system was completely messed up in the youtube update about a year or so ago,most people hated it and various pettitions were ignored unfortunately.As I have been uploading vids since 2008 I noticed a vast difference in the rate of comments and ratings.I used to get on average 7-10 comments a day,since the update I'm lucky if I get one a week.So much was spoiled and it seems to only help the publicity of those who already get thousands of views a day.Thanks for nothing youtube!