Because there are a certain percentage of regular forum members who take great pride in looking at others feedback to see how much they paid for something they are then on selling, so they can lay the boot in and tell you how terrible you are. Despite the fact they buy and on sell themselves.

It is also a reason why some people don't leave sellers feedback when they plan to on sell something, so there is no record of it in their feedback for busy bodies to see.

I collect mineral specimens. I will buy several of the same thing, pick what I consider to be the best ones for myself and then sell the rest. That is my right to do that, but some people think that people like me are ripping off unsuspecting buyers. If someone doesn't want to pay the price that I have listed it for, they won't buy it, simple. If I could have my feedback private I would. Yes, I could open a second account, but I really can't be bothered with that.