If you can't do something at a real auction, you shouldn't be able to do it at an on-line auction. This would include sniping.
The idea about "well, the bidder should have set their max bid higher if they really wanted it" is rediculous. That is NOT the way an auction works. If this were the case, everything would be "Buy It Now"...... the very nature of an auction is so that the bidders can play against one another. This allows 2 things to happen:
1. The bidder wins at a price he is comfortable with.
2. The seller is awarded a fair price for his sale.
Sniping does NOT allow condition #2 to be met in many cases. It is strictly an immediate advantage to the bidder, and everyone else is hurt because of it. Think of it as selfish.
In the end, however, even the sniper runs out of luck. eBay is large enough that it is looked upon as the market-value setter for many, many items. Sniping effectively lowers the average selling prices of goods on eBay, thereby lowering the product's overall value. So by sniping, everyone will lose out at some point.
Anywayz, these are just my thoughts on the subject.