The auction you showed for hrh.on.ca is a really good example of the issue I was trying to explain and which raider paraphrased rather well. Allow me to expand...
In this auction the last bid placed by "you" was $200. The auction went on between two parties in a span where bids were being placed at about 1 per minute. And while you might ask why didn't these bidders use proxy bids, I can't answer that.
But, back to the popint at hand. If the winning bidder in this auction was declared void and we followed your suggestion, then the second place bidder would get the domain for $210. One increment higher than the third ("you") place bidder.
Isn't it possible that in the flurry of the last 16 minutes where the two bidders were furiously bidding against each other that "you" would have liked to place a bid higher than $200 but was never able to place a valid bid because it was being bid up so fast?
It's not an issue of whether "you" gave up the bidding or not, it's whether the quick bidding of the other parties locked you out? Clearly, "you" did not want to bid more than the winning bid, but perhaps "you" wanted to bid more than their last bid of $200 but never could? I have had situations where simply awarding on the basis of the third highest bidder plus one increment has prompted criticism because the third hihgest bidder would have still been active in the auciton at that level.
The main point here is that by voiding the winning bidder, in many cases this would return the auciton to a "level" where more people may have gotten involved if they could have. And proxy bidding only makes it harder since the two final bidders would only bid up the auciton faster.
Our process allows for the second place max bid to stand or a re-auction occurs. And as I said earlier, the choice is there for the second place bidder to make. They don't have to accept and in fact could simply re-enter the new auciton with a proxy bid the same as their previous high bid.
Some people would also argue that having a re-auction is not fair either because the previous winning bids are known in advance and this will affect the overall bidding.
Ultimately, I guess any approach will not satisfy everyone. I feel our approach is a good compromise for all.