Counterargument: there are cases where feedback is very important, even if you discount the content of the comments as mere opinion.
Most users are (rightly) hesitant to make a large purchase from a seller with no feedback, but would not hesitate to make the same purchase if the seller has a history of positive feedback for sales in the same category. Without a feedback system of some kind, all eBay sellers, from the largest retail outlet to the newest account registered today, are all indistinguishable zero feedback accounts as far as the buyer can tell. Without feedback, there is no way to tell if the seller is actually delivering anything after the items land in the sold column.
See here for an example where feedback reveals a lot about a seller (US link):
https://community.ebay.com/t5/Buying/How-to-read-a-seller-s-feedback-page-and-spot-a-fraudulent/m-p/...
I think putting up with a few rambling, disjointed feedback comments is a small price to pay to be able to identify all sorts of scam listings.
Feedback may not allow you to always distinguish great sellers from good ones -- any seller can run into a buyer having a bad day and get an undeserved negative -- but feedback can allow you to distinguish between good sellers and sellers that should be avoided at all costs.
