Hi all! Thanks for posting your concerns.
If you haven't read my reasoning behind the removal of the negative recommendations feature yet, please do so: https://pinside.com/pinball/forum/topic/negative-recommendations-feature-removed
In short: giving Pinsiders the ability to leave other Pinsiders unsolicited negative feedback, without having any evidence of an actual sale taking place is the base of this issue and the reason for removing the 'feature'.
The current system is simply dependent on the seller inviting the buyer (which is not likely to happen if the seller knows beforehand that the feedback will be poor). Could there be another way to link buyer and seller? To make sure that feedback is legit, or at least based on an actual sale taking place? Right now, I don't see it but open for suggestions!