This a very one linear way of looking at the world. Sure, it might be about "power games" but feelings do matter and morals too and how one feels about it does

This a very one linear way of looking at the world. Sure, it might be about "power games" but feelings do matter and morals too and how one feels about it does give you the extra energy and drive to succeed at a (re)negotiation. So... how can one ignore all that? The original debate was if it's unfair. I think taking advantage too much during an initial negotiation is unfair but since the other side did agree it is a "fair" trade for the other party (based on the partial info they had). Once extra information is revealed, the trade is not fair in retrospect. But new information should only apply to future trades: as such, negotiating or quitting is moral. You might be sub-estimating how good people are at power games. Quitting out of spite is know to happen so people are willing to take a loss due to unfairness. Assuming rationality and ignore feelings and morals while focusing only on the technicality of "power games" is super simplistic.