(Full disclosure, I am biased here. I run a
donation based escrow. But I believe my arguments are sound.)
There is no risk to the scammer by using donation escrow or not using it - either way they won't get the money, but if they do use it, at the very least they can use it to fuck you so you don't get your money back in the event of a default. On top of that, they can also be used as a harassment tool even if someone isn't a scammer in the sense of them trying to take your money.
There's no risk to a scammer without a donation escrow anyway, since pretty much by definition they have nothing to lose. What the escrow service does is remove the
incentive to scam somebody, not remove the non-existant
risk to the scammer. The scammer has no reason to invest time setting up a con because the net return is a negative. They use a resource, their time, and if there's no possible way to profit, they've lost out. Hence they'll move on to the next potential victim, or try to pester you into not using escrow for some BS reason, and give up when you refuse to budge.
Yes the donation system isn't perfect. But a perfect system is expensive.
Real world analogy. Sometimes I mail something out that's 25 or 50 bucks. I don't spend the money on insurance because it's too much from my perspective. If I was mailing something that cost $500, then I buy the insurance right at the post office. If I'm mailing a Picasso painting, I need to get insurance from Lloyd's of London and hire a private courier to deliver the goods.
Similarly, I buy a .25 BTC bumper sticker, I'll just take the chance on a loss. If I spend 5-10 BTC for something, I want some lightweight protection, but don't want to pay a lot, because it adds up, so I use a donation escrow. If I spend 100 BTC on a new laptop, then maybe I'll look into a full-service escrow.
An escrow service requires an arbitration process. Any escrow service without an arbitration process is nothing more than "Hey Bob, will you hold my wad of cash for a few days?" And you don't know Bob. And Bob might give your money to the Red Cross if the seller tells him to.
No. The person who gives the cash to Bob determines if it goes to the Red Cross. The more comparable scenario is giving money to Bob, and saying, "If you don't here from me in a few days, burn that money, flush it down the toilet, but whatever you do, don't give it to that jackass." The seller can not force a charity release and somehow steal my money. If buyer is an actual scammer, they won't put the money into escrow in the first place, because they can't get it back. Once again, the
incentive to scam is removed, because it becomes impossible to profit. Yes, conceivably a person could just not release the money after you've sent them, but what incentive to they have to do so? The number of people who would just do that to be an a-hole are far less than the number of scammers out there.
Also, if the deal falls apart for legitimate reasons, and both people are on the same side, you can recover your bitcoins safely. This is covered in my FAQ.
As far as feedback/ratings go, there's already a site, it's called HEATWARE. I use it on here as well as other forums. It should be the standard for here, just like it is at so many other For Sale forums around the world.
I don't understand how a donation based escrow could be used as a harassment tool. The only thing I could think is that someone can keep on bugging you to release the coins. But they could do the same thing without the escrow service, by bugging you to send coins. Could you elaborate?