I agree with Jo. Helpful ratings and comments are often based on popularity of the author or controversiality of the topic, not quality of the review. This would simply give the most popular and/or controversial people higher visibility, not necessarily promote the best and most helpful reviews. It might also foster cliques who agree to rate and comment on each other's reviews to move themselves higher up the visibility list. That's a long shot but a few of us have seen things like that happen elsewhere. Interestingly, that "elsewhere" was named in two of the 10 reviews in your list!

--Bob (who's feeling contrary today.)