The logic still seems broken to me, and it's largely because you assume you're the only person that's bidding last minute, and that the person whom you are bidding against hasn't entered their max bid from the get-go.
Let's say your max is 90 bucks and you bid in the last 20 seconds, and I do the same but with a $100 max, then I win. It didn't matter one bit that you waited until the last second to bid. And if $90 was your max and there's a bidding war going on, or I had bid my max of $100 on day one, then it wouldn't have mattered anyway. Other people will be bidding last second, and that gives you just about zero advantage.
Sure, if one guy is bidding and hasn't entered the highest price that he's willing to pay, AND doesn't do a very good job of watching the auction at the very end, then you are correct, it will be easy to outbid him last second and win. Assuming that someone bidding against you in the last 30 or so seconds "doesn't know what to do" is just that, assuming. You "know" what you're doing, so you could just as easily assume that he does too.
I've bid on PLENTY of auctions where someone has chipped away until they hit the max bid that I or someone else holds in the last minute or so. Whether they chip away with 30 days left or 30 seconds doesn't matter, there are folks that will do so either way.
The method that you guys prescribe may have an amount of efficacy in certain, rare instances. But it's hardly the norm, at least in my experience with eBay in the last 13 years. All that said, I've employed your variety of tactic in the past. I found it both time and energy consuming, not to mention a waste of both on most occasions.
EVERYONE has a price limit, sniper or not. Racing against the clock doesn't guarantee that yours is the max or that someone else isn't a better sniper than you.