One bad apple might not spoil the bunch, but it does a pretty good job of stopping the rest of the bunch from having the opportunity to buy, in many cases.
The fact is that most people will put themselves into a position to get screwed over, only once, before they pull out of selling on line. No matter how good the rest of the buyers (apples) are, they simply won't get the chance to prove it, because it isn't worth the risk to the seller.
Whether one bad apple spoils the bushel, or not, the opportunity (at least from that seller) is gone.
