There's penalties for sellers if you stop an auction when there's already bidders. So there should be penalties for buyers as well. Like having your account locked if you're a repeat offender of breaking rules.Maybe they’re doing this to try and stop time wasters? people bidding and winning auctions. But then deciding they want to pull it after the auction ends.
Happened to me a number of times, I lose a sale, and have to relist the item. Really pi55es me off! You can’t even report the bidder or leave them negative feedback for doing it!