Ok, it's not a sniping system. It's as effective as, if not more effective than, a sniping program for eBay's purposes: Allowing people to say how much they are willing to pay, then walk away from their computer.
Also, if it were a sniping system, I suppose they'd call it a sniping system.
My point was simply that there is no need for eBay to implement a program that is essentially a less effective tool than the one they already have, or that would work in conflict with the one already in place.
Also, from a financial point of view, bidding wars may be in eBay's best interest, as the emotions involved in a bidding war may result in a higher-than-expected winning bid. I know from my own experience using the proxy system. I thought $25 was the most I'd pay for something, and proxied it. Then when I was outbid, I realized I was willing to pay more and more, until I finally had to conclude that I'm a sucker and Buy It Now is better for my wallet.