well I think the point is that the method currently used is skewed in favour of the seller. If I leave legitimate negative feedback for a bad seller he undoubtedly will leave negative feedback for me even though I have paid on time and have done nothing wrong, I still get tarnished with negative feedback, hardly fair is it.
For instance, recently I bought something from the USA, the seller charged me $27 postage, supposedly priority UPS 3 day shipping, the goods arrived about 3 weeks later and the actual postage cost written on the package is $2.20, so what do you do, leave them negative feedback?? sure, they then will more than probably leave you negative feedback in return, so what do you do.
Basically feedback is skewed in favour of the seller atm because people are in fear of receiving negative feedback on their account even though they probably don't deserve it and the seller does.