The staffs in most bookstores here in the greater Washington area tend to be heavy left quisling types, burnt out RDDBs from the 60's, etc. Try buying any conservative title from a bookstore around here - it is difficult even when the title is red hot elsewhere in the country. Part of it is tampering by the staffs themselves and part of it may be that here in the Belly of the Beast such titles don't move well. But to see Amazon pulling such crap is a real shame.
With the release of many new products, there are often disgruntled former employees or others with an ax to grind showing up--and also shills for the product itself. People are catching wise to how meaningful and meaningless the reviews are, particularly people who read. But I've not seen selective censoring of reviews...yet.
We may well see the return of these reviews.