Something along the lines of “when you cooperate, your opponent is forced to cooperate too”.
The reason it is optimal is it presents no chance to be defected against, and any situation where you are defected against is worse than every situation where the opponent cooperates.
Lacking this magical trait of superrationality, the chance of being defected against is drawn back in, which dramatically harms you cooperating, making it less optimal.
Something along the lines of “when you cooperate, your opponent is forced to cooperate too”.
The reason it is optimal is it presents no chance to be defected against, and any situation where you are defected against is worse than every situation where the opponent cooperates.
Lacking this magical trait of superrationality, the chance of being defected against is drawn back in, which dramatically harms you cooperating, making it less optimal.
That would be something that made more sense but just isn’t something that fits in that context.