Just to point out the other side of the issue:
Feedback provides a little bit of security to new members. For example- imagine a senario where a co-op vendor completely botched a whole co-op. "Everyone" knows about it, so "no one" would buy from that person again.
(I used quotes because not everyone on the whole site would be aware of the issue even when it feels like it).
Fast forward a few years when that vendor tries again.
Do you sit by and watch unsuspecting people get taken? Do you let newbies know? Do you want to get involved?
What level of duty do you take to keep people safe?
Dave and I are totally hands off when it comes to trades and co-ops. It is "at your own risk", period.
Feedback does give a little bit of warning and help and heads-up to the newbie.
Trust me, we're more than aware of the pros and cons of each.