everyone would be better if everyone is cooperating
I agree with this view. And as I was not claiming that it would be good to be too much biased and always (or too often) defect. However, if there is a general tendency of how often / how likely do all the groups defect and cooperate, then one group who pledges to never ever defect no matter what, will see that the other groups will defect against it, solely because they know they will always win. The solution of the prisoner's dilemma requires the possibility, or at least the ability for you to defect, even if you don't choose it. Otherwise your opponent will always defect.
This sort of thinking seems bad:
This sort of thinking seems socially frowned upon, but accurate:
Similar points could be made by replacing a/b with [group of people]. I think it's terrible to say something like:
But to me, it doesn't seem wrong to say something like:
Credit and accountability seem like good things to me, and so I want to live in a world where people/groups receive credit for good qualities, and are held accountable for bad qualities.
I'm not sure though. I could see that there are unintended consequences of such a world. For example, such "score keeping" could lead to contentiousness. And perhaps it's just something that we as a society (to generalize) can't handle, and thus shouldn't keep score.