Brumby, I suppose I veered off-track a bit with my reply...! (I really did want that Georgian silver.)
Getting back to the main question, it's not just that eBay was been hacked; it's a number of other factors which may conceivably be hurting buyer confidence (in terms of being a buyer on eBay, that is).
• eBay is perceived as being very closely associated with PayPal (as of course it is, in the sense of PayPal's ownership). Therefore, a compromise of details on eBay will lead at least some people to fear that their financial (PayPal) details are also compromised.
• eBay was touted as being safe. It's now exposed as being no safer than any other ecommerce site.
• eBay's security was certainly never anywhere near as high as, for instance, an Australian bank's online site - but because of eBay's own message of safety, it is likely that some people will confusedly think that very high security sites such as, for example, the ANZ bank online, may not be as safe as it is claimed. eCommerce in general may be affected, and this in turn may affect potential new eBayers. That is, it's not just that eBay will be thought unsafe because the security breach occurred on eBay, but eBay will be thought unsafe because a security breach occurred on a site considered very safe which means that online buying perception is affected which means eBay is affected because of that GENERAL lowering of perceived safety for online buying. It's a flow-on affect. (I hope that makes sense.)
• eBay failed to notice the security breach until some time later. This speaks volumes about eBay's security system; not only can it be mugged, but it won't even notice it's BEING mugged.
• eBay failed to notify its members - until the news was reported from an external source. eBay then issued a brief statement and asked members to consider changing their password. (That subsequently became "You MUST change your password" - but there was no notice to that requirement until members were trying to log in... but that's another story.) The real problem here is that eBay buyers have the sense that eBay would not have informed its members of the security breach at all... that it was "forced to" by being outed by an external news source. Hence eBay buyers feel not only unsafe, but deceived, disdained, disregarded and despised.