Earlier quoted context omitted.
Presume this is an experiment or phased rollout. I was just on Amazon and only the first page of reviews are visible if logged in and no reviews are visible if logged out. edit: It seems badly done too as the (140) count next to the stars still links to the review section below the description's anchor but simply does nothing onclick due to the fact that the whole destination div is gone.
they broke a lot with the reviews for this experiment. e.g. filter by stars no longer works, but the link to it is active.
Things are going great