"it might motivate some of them to rise up the ranks when vacancies occur and be more determined to do things better and not repeat past mistakes."

Wouldn't that be nice? I have no empirical evidence whatsoever, but my default viewpoint is that employees who challenge the way their employer operates (even when they have the company's and/or its customers' interests at heart) are among the least likely candidates for promotion - that usually goes to the 'yes'-men (or women), the ***-lickers. I've witnessed it myself - admittedly not in the high-flying corporate sphere, but in other work contexts. In previous jobs I've challenged certain practices - not aggressively, but reasonably - and come up with a few genuinely good ideas (although I say it myself) which would have cost little to nothing to implement, but which would have resulted in a modest decrease in expenditure and/or a modest increase in efficiency. For the most part, these were totally ignored - for all the suggestion boxes and 'Our employees are our most vital asset - we welcome, and act on, your feedback' corporate platitudes, managers hate their underlings coming up with innovative, or even just moderately good, suggestions. It hurts their pride too much to have to admit (even to themselves) that someone beneath them has thought of something that they haven't. Perhaps that's partly borne out of a fear that this bright spark might at some point become a threat to the security of their own position (and, for the same reason, many managers don't even like 'lesser' employees who show 'too much' enthusiasm). Unless they think there's a chance that they could get away with claiming the idea for themselves, they will usually stamp it into the ground. Maybe I was just working for the wrong companies, but I strongly suspect that my experiences were very far from unique.

What you suggest would only 'work' if those employees were adept at biting their lip and keeping their thoughts to themselves while toeing the line. Even if they were promoted, and that fire within them had not long since died, the surrounding environment and other factors could still prevent them from bringing in real change. They would have to be very near, if not right at the top, of the greasy pole in order to effect a significant shift in corporate thinking, policy and practice.

At the moment, I feel that the alternative you mention is more likely. I don't want that to happen, purely out of self-interest. I want eBay to get its s**t together now so that it's still here in 5, 10, 15 years and beyond.

As you can tell, I'm in a relentlessly cynical mood right now!