Interesting. If I'm researching anything for a possible purchase on any site, be it C-Net for electronics, gun reviews, or Amazon reviews (which I still use), I ignore any ranking without some text. I then read the text to see why the item is getting a good review, or why not. I can then sort through for useful information, and ignore negative comments that mean nothing to me and my needs.
Using reviews as weapons...nothing new, just a side effect of the Interweb age. A lot of lawyers doing divorce work have gotten jammed up leaving negative reviews on a competitors site. A car salesman friend says that happens in the dealership world a lot, too.