Amazon makes past reviews difficult to access. I could see only 5 reviews per view, then you click the forward arrow for 5 more. It takes too long. And if you leave the page, you lose your place.
Keep in mind, there are reports that many online reviews are fake. For example, this article in the Guardian: http://www.theguardian.com/money/2013/jan/26/fake-reviews-plague-consumer-websites
I wanted to quickly research a product on Amazon. There were over a thousand reviews, so let us see them! It would appear Amazon is hiding past reviews to protect the seller. How about protecting the consumer with a VIEW ALL REVIEWS button? Also a button to see ALL BAD REVIEWS? I think it's a scam.