Essayist: Only happiness is intrinsically valuable; other things are valuable only insofar as they contribute to happiness.
Background
The author thinks that happiness is the only thing valuable in and of itself. Other things are valuable if they contribute to happiness.
We don't approve of a bad person's being happy.
Some people think this shows that . And they think this then entails that
But, the happiness people deserve is determined by the amount of happiness they bring to others.
Evaluate
I'm pretty lost here, but I blame the philosophers, who seem to be making weird leaps of logic. The fact that we don't approve of a bad person's being happy doesn't necessarily show that we value happiness only when it's deserved.
Maybe we just value happiness only when it's ours.
It also doesn't show that we think something besides happiness is valuable. Maybe we just don't want bad people to have things of value. Depriving them of things of value makes us happy.
The author is pivoting against the idea that , so she presumably wants to conclude as she began: Nope, we only find happiness to be intrinsically valuable.
But she's not going to conclude something she's already said. So given that her motivation is to defend her claim that only happiness is intrinsically valuable, her final Therefore claim should be something that manages to explain away the fact that we don't approve of bad people being happy, without it meaning that we value something besides happiness intrinsically.
But it should also use the principle that .
Fill-in-the Blank
So,
That's a way to explain why we don't want bad people to be happy while still making it seem like it's all about happiness.