Thing is, people have become used to it. An 8 is a good score, but many people seeing an 8 will worry that something was not quite right and not make a purchase as a result. Quite frankly, if the seller gave me the weight, dispatched when they said, and provided good stealth, I'm happy to provide the vendor a perfect and well deserved score.
I'd like to see more people take the time to actually do a written review. A description of what they have is miles more useful than an arbitrary score would ever be, and I love to see people take the time to photo and critique the product. It provides so much more insight.
I'm just as guilty as anyone though, plenty of product bought and I've not reviewed one! Mind you, I'm buying hashes and I've not had one I've not been really happy with yet, so mine would be all gushing with praise :)