I think the viewers have become more discerning over the seasons and use the judges' opinions and knowledge to form their own.
I hope that viewers don't use the judges' comments to form their opinions. Bruno and Carrie Ann really know almost nothing about ballroom dancing and their comments are usually somewhere between inane and nonsensical. Len has the knowledge but his comments often aren't much better. There are a lot of basic technical issues which the judges don't address, and it's usually very obvious to me which celebrities have large fanbases based on the comments they receive vs. their performances.