The only non-positive feedback I've ever received was a neutral from a buyer not happy with the guitar she had bought. Just one problem, I hadn't sold a guitar. It was an error by a newbie who had left a feedback for me that was intended for another seller. Getting that corrected was like pulling teeth despite the buyer writing eBay several times confessing she had left the feedback for the wrong seller.
eBay cares about nothing but the money.
I just closed my ebay store. The listing is invisible unless you also have an item on auction. I don’t want to mess with auctions, that’s why I opened the store, dammit. What crap.