One has good and bad experiences with many things. Go to a restaurant that you really like and have been going there for years. Great food, impeccable service and reasonable pricing, until the one day that you recommend it to someone or you bring a friend along. The same goes for buying something at a store or ordering by mail, there may be gitches or they're having a bad day, so we have to filter out those "one time" or "unusual" occurrences and try again. New business also need a break to get their procedures ironed out and new personnel up to speed. On the other hand, some of us have more patience than others or are more tolerant and so setting up a rating system is really very subjective and in some cases not very fair. Yeah, there are the bad apples who would take your money and run or couldn't care less about customer service, and the word gets around quickly.
Anyone can open a dialog with others about good and bad experiences with a vendor, I know as a manufacturer, I found it bothersome if someone had an issue with us that affected our relationship and we didn't know about it. We would bend over backwards to make it right had we only known, so some vendors would also welcome criticism. We always welcome a healthy, honest discussion about things like that, but occasionally, some people get carried away and we have to enforce some control. We will not dedicate a forum to this since we've had success with people just opening a thread and voicing their opinions. We do watch these threads closely though since we don't condone product or business "bashing", or flaming. No, "this product stinks" no, "these guys are lairs and cheats" or no, "you people don't know what you're talking about" stuff. Just the facts, and we have to admit, this thread has been very good in avoiding things like that. Those that have contributed to it so far have to be complemented.
If you wish to rate a vendor or a product, that's fine too, just remember that it's a subjective opinion, but it's also something to take into consideration when dealing with these people.