I'm not hammering on anyone specific, but there are lots of other computing sites with markets that have ratings systems. Heck, i'm in one GB where the host has had the items in hand for around 6 months now, and still has not shipped them out. I really don't care that much for that buy, but there are lots of people that do. If people leave neagtive seller ratings, it would basically be a warning to people that the Host may have issues, break deadline promises, or other problems.
But yeah, on here everyone will throw money at anyone with a ms paint mock up and a promised delivery date of 2 months later.
From my personal experience, there are only 3 people on here I feel comfortable giving a good bit of money to in a GB.
And with a user rating system, it would not be any more part on the moderation of the site.
Seems like a simple enough system, and as big as the GB and classified market is on here, it couldn't hurt anything.
I've had a bit of bad luck on here in the past, sellers mailing broken items, shipments gone 'missing', people delivering items a month after payment ( from classifieds ) and other issues. While I know its buyer beware, a feedback system sounds like a good idea to me. I don't see any negative reason for not having one.
and back to my OP, mostly its new people who join in and see the promised 2 month delivery, then complain endlessly about delays, lack up updates, etc.