I don't think your first paragraph is compatible with your last paragraph: I pointed out the "this is why we can't have nice things" argument specifically to note that it doesn't apply here, as this isn't a nice thing... and you agree with me... which means you are actually defending a world with bad things, and are arguing on the side of the actual scam artists: the people behind these systems you have yourself now called "manipulative" and "repugnant". You have chosen to defend an entity that makes money by taking advantage of dumb psychological bugs in humans, a process they do deliberately and opaquely (as if people knew too much it would harm their business), against another entity who was transparent in their dealings. This makes it difficult for me to accept at face value the moral high ground you have taken in this argument you started :(.

As for your paragraph about scam artists not being defined by the people they are calling dumb, I tried to make the key difference very clear, but maybe I wasn't quite direct enough for it to be noticed: if you take the time to report the issue to the other party, if the scam artist actually says "you realize this is a scam, right? I leave from this with all of your money", and the other party still insists they want to perform the transaction and even helps you do it, I don't see how you can believe it is a scam. What makes a scam artist morally bereft is when they lie or hide their cards: AVIS was actively playing along with this scenario.

Put another way, to believe this is a scam would also require thinking almost any transaction anyone makes ever is a scam, as the entire reason people ever buy anything is because the value they assign to the good is at least slightly greater than the value the other person assigned to the good (which is good for everyone as these transactions are generally non-zero sum). I personally try my damndest to make certain that all of the merchants I use on a daily basis make money on me, as I want them to value my patronage, even going or of my way to pay extra for things that they market as "free", so I truly get where you are coming from... it just doesn't apply here, and you haven't yet connected the dots.

To make the picture even more complex, it isn't ever clear who is making money from what other players. AVIS is giving out EuroBonus miles. Maybe EuroBonus really really wants people to have miles and use them, as they get a kick back primarily from airlines for them being spent, and so they have encouraged car rental companies to give out these offers. Maybe the reason that the branch manager found out from their boss that it was OK to do this was because it actually makes money for AVIS. You just don't know here, but thankfully, AVIS clearly is informed enough to make the decision for themselves: they know these schemes have these holes, they know these schemes are designed to manipulate peoples' incentive structures, and they were even informed of this particular instance. The way this guy keeps saying "I told them what I was doing, expected them to stop me, and they cheered me on" is really telling about his ethics here.

Don't get me wrong: I agree scam artists suck, but the "false exclusion" you are trying to pin on me is clearly unfair :(. Like, if we are going to start throwing "rules of argument" stones, you still haven't defined scam in a way that is precise enough to include this person while excluding AVIS, Sony, or someone buying a house. The only definition to date is essentially "net negative to society for the transaction", but you actually have admitted that the entire pricing model of travel is "another giant waste of humanity's time". If you are going to cast such damning aspersions on to people--calling them scam artists, comparing them to pick pockets, and likening them to parasites--it would be good to at least provide some guidance as to what, specifically, they actually did wrong.