Of course it is a farce, it is a pat on the back which makes some buyers feel good and anything that does that is a good thing.

You did the right thing and leaving neg feedback for that non payer would do absolutely no good whatsoever, now if they don't pay for another item and the seller goes through the UIP the buyer will not be able to buy anything from sellers who have their buyer blocks in place, I hope you do. Also add them to your blocked bidder list.

If sellers left pos feedback with neg comments it means they did not go through the UID process which is why the numpty buyer was able to buy from you even if you had your blocks in place.