Hello 'iamonek',
<<. . . a new bidder jumped in and won. . . . he didn't respond to my immediate congratulations>>
Did you really think he should? He simply sniped an item, -- he didn't have a baby. 
Some people are more conversational than others, and likely your winner is not much on chit-chat. All you really need to worry about is if he pays. If he doesn't, after 3 days you can send a friendly note of congrats with a cheery reminder of payment at that time.
<< I have no objection to a person sitting at a computer and trying to 'snipe' manually.>>
Oh good. At least you don't object to that.
The only person who would accuse a sniper of being a "bid thief" is someone who did not bid high enough to win the item and was evidently hoping to get it for a lot less, but lost out to the winner who was clearly willing to pay more.
Perhaps I don't quite understand your complaint. Are you saying you would have preferred to receive less money? I suppose there are people for whom their unique brand of equalitarian ethicism trumps all, but it would be the first I'd heard of a seller who wished the bidding had not gone so high.
Whether an item is sniped by a bidder crouched over the keyboard counting down the seconds waiting to Zap! in his high bid at the last second, or a bidder who has placed his high bid with an e-sniping service and then gone to work, -- the end result is the same. Behind either bid is a real person who has decided on a 'highest possible' amount.
Wouldn't you rather have the biggest bid?
I truly do not believe that e-sniping is in any way deleterious to auctions, as it is just another sniper. New users quickly learn that sniping is often the only way to win, but again, it will be the largest amount that cinches it. E-sniping enables more people to bid on auctions because they can have a bid entered when they need to be elsewhere. Without it, too few bidders rarely results in high auction prices, unless there just 'happens to be' two persons vying for the same thing and are willing to go the distance.
Auctions can be a lot of fun, but many times people just want to buy the item, particularly for every-day utility objects. If a desired item is fairly priced it is usually just easier to buy it and get it on its way.
After all, on an auction if you've got 10 people bidding on an item, only one of them will walk away happy. To the rest of them, those similarly priced 'Buy-it-Now' items will look awfully appealing.
<<What 'coulda-woulda-shoulda' eBay do? Use a 'prove-you-are-a-person' validation on the bid input. (Type an image content into a text box)>>
Goodness, no, - this isn't school where students have to show up in person and present their ID to write their own exams. No matter how a bid is placed it gets there because someone has a maximum he is willing to pay. With more and more bidders than ever, the popularity of auctions has not dwindled, but many people may simply choose a reasonably priced item to get it on its way and will have it in their hands before the other person's auction ends. No surprises, no disappointments. Just stuff.
You're welcome to your opinion and if you truly prefer lower prices and its resultant income reduction, well, I suppose we all wish for something.
You might ask yourself what is ultimately most important to you, personally, however.
