Let’s consider a given preference from the point of view of a given outcome after choosing it, in which the preference either exists or does not:
1. The preference exists:
a. If there’s an outcome in which the preference exists and is more satisfied, and all else is equal, it would have been irrational to have chosen this one (over it, and at all).
b. If there’s an outcome in which the preference exists and is less satisfied, and all else is equal, it would have been irrational to have chosen the other outcome (over this one, and at all).
c. If there’s an outcome in which the preference does not exist, and all else is equal, the preference itself does not tell us if either would be irrational to have chosen.
2. The preference doesn’t exist:
a. If there’s an outcome in which the preference exists, regardless of its degree of satisfaction, and all else equal, the preference itself does not tell us if either would have been irrational to have chosen.
So, all else equal besides the existence or degree of satisfaction of the given preference, it’s always rational to choose an outcome in which the preference does not exist, but it’s irrational to choose an outcome in which the preference exists but is less satisfied than in another outcome.
(I made the same argument here, but this is a cleaner statement.)
Fehige defends the asymmetry between preference satisfaction and frustration on rationality grounds. This is my take:
Let’s consider a given preference from the point of view of a given outcome after choosing it, in which the preference either exists or does not:
1. The preference exists:
a. If there’s an outcome in which the preference exists and is more satisfied, and all else is equal, it would have been irrational to have chosen this one (over it, and at all).
b. If there’s an outcome in which the preference exists and is less satisfied, and all else is equal, it would have been irrational to have chosen the other outcome (over this one, and at all).
c. If there’s an outcome in which the preference does not exist, and all else is equal, the preference itself does not tell us if either would be irrational to have chosen.
2. The preference doesn’t exist:
a. If there’s an outcome in which the preference exists, regardless of its degree of satisfaction, and all else equal, the preference itself does not tell us if either would have been irrational to have chosen.
So, all else equal besides the existence or degree of satisfaction of the given preference, it’s always rational to choose an outcome in which the preference does not exist, but it’s irrational to choose an outcome in which the preference exists but is less satisfied than in another outcome.
(I made the same argument here, but this is a cleaner statement.)