Agreed. Ebay protects/coddles buyers to a fault, and is seemingly hostile to sellers. Sellers cannot even leave negative feedback for buyers, AFAIK. I signed up in 1998 and Ebay was much better/fairer then. Even the search function worked better.
A few random points regarding eBay... (This ended up being a lot more writing than I thought, so pull up a chair and make yourself comfortable.

)
It has not been possible to leave Negative (or even Neutral) feedback for buyers since May of 2008. Prior to that there were endless fights between sellers and buyers, such as sellers threatening buyers with Negs unless they agreed to drop their feedback first, or not demand a refund or whatever. Feedback has been lopsided to the buyers' advantage for the past 17 years now, though the Feedback percentage rating itself does not have a bearing on a seller's account standing.
eBay will remove feedback that violates a narrow set of circumstances, although it might take a bit of work to achieve that. A seller can also send a feedback revision request to the buyer, if they have resolved their difference and the buyer agrees to revise their rating and/or comments.
As for auctions (which I understand are now only about 20% of listings these days; BuyItNow pricing predominates, and a large percentage have Make Offer bargaining available as well), a bidder can retract a bid himself without seeking permission from either eBay or the seller. (Terminology-wise, sellers can
cancel; bidders can
retract.)
A buyer's bid retractions go on his record, and his count of retractions over the past 12 months can be found in the desktop ("classic") view of his feedback page on the Feedback Left for Others tab, right side, about halfway down. His 30-day retraction count can also be seen on the auction's Bid History page. Click on his disguised bidder ID there, and it will pop up a 30-day history of his bidding activity. (If you are the seller of that auction, you will need to log out first, so that your bidders' IDs are disguised when viewing your Bid History page.)
If a seller cancels a bid, that does not go on the buyer's retraction record. Some buyers will feign ignorance about how to retract a bid for that reason, asking a seller to cancel it for him instead. I generally just ask a bidder with cold feet to leave his bid where it is, because it will probably get sniped at the end anyway, and cancelling it for him will just surprise the second-place guy (as
@mike1117 mentioned). I tell him that if he does end up as the winner and still wants to cancel, I can do that. Sending a Second Chance Offer to the next guy down on the list works for me about half the time, and gets me almost as much money as what the winning bid was, less a maximum of one bid increment. In fact I sell most of my auctions via snipe bids in the final seconds anyway, so I don't get too concerned about bidding activity earlier in the week.
It's true that a bid is considered a commitment to buy if the bidder wins, but the reality is that it's unenforceable if a bidder retracts; you can't force a buyer to pay. Taking the buyer to court would require far more time and effort than it's worth.
As for calling up eBay, that option has been gone for several years now. The way to speak to someone at eBay is now to go through the Chat option and request a callback. Any supposed calling-in numbers for eBay that you might find on the Internet are either old contacts or scammers who will cheerfully take your account info but not do anything to help.
Speaking of "not do anything to help," the eBay callback drones are notoriously bad, and powerless to help. They read scripted response trees based on what they think you need or are asking for, but generally just want to wrap up your call and move on the next. (Demanding to speak to a "supervisor" will more likely just get you handed off to the guy in the next cubicle.) You're better off seeking advice from the eBay Community groups, which are populated by other experienced users who can probably give you more accurate answers. (They may not be answers that you want to hear, but if someone posting there offers bad advice, there are plenty of others who will jump in to correct him.)
eBay Selling Community Group:
https://community.ebay.com/t5/Selling/bd-p/selling-db
eBay Buying Community Group:
https://community.ebay.com/t5/Buying/bd-p/bidding-buying-db
For all its faults (and boy oh boy do they have faults), eBay is still the biggest market out there. I wish selling would go more smoothly, but I'll take what I can get.