I've had sellers chase me for feedback on another site and I find it really rude. Feedback is left at the buyer's discretion. A seller sent a rather blunt email to me this morning asking for feedback on a computer I collected last week. I was just in and out without wasting his time by seeing it working. The monitor has a burnt pixel and it didn't come with the speakers listed, but I ignored that. He's a nice guy and I plan to leave him positive feedback when I get round to it, but one shouldn't demand it. It's just a transaction to me. Considering you could be negged by an idiot over something out of your control, no feedback can be considered good feedback!
I once ordered a video game and the case was dirty. The disks were scratched but luckily worked. The seller emailed me every day for a week until I left feedback! I've never negged before in my life but he almost asked for it Last week, a seller with 50% positive feedback refused to let me collect an item I won because the winning price wasn't enough for him. I haven't negged him either but I wasn't expecting him to honour the transaction due to his previous neg
People may have a private reason for not leaving feedback, Demanding it would be like playing Russian Roulette to me