The above reply from Brad sums up the issue; I'll explain:

The gamble of eBay still exists greatly for the buyer, and still benefits the seller. The fact is that when the proxy bids come in a day early or last second there will be a winner. Users abusing the proxy will either pay much higher than expected or gain negative feedback for non-pay. Knowledge of the most effective bid process is the key for every auction genre you attend online or in person. If you don't know eBay; learn more effective bid processes to increase your odds of winning.

Simply put, if you remove the dreams of granger from the buyers searching for that next bargain, then you will lose the popularity of the site altogether. If a tactical advantage is exploited, level the field by using the same tactical advantage and it boils down to who placed the highest bid when the buzzer sounds. That is the magic of eBay folks.