Culture and Happiness
Happiness, it seems, is more about cultural expectations than it is about material wealth in the abstract. When people feel that they have as much as the others in their society, they are happy; but when their culture dictates that they ought to have something else, they're likely to complain about whatever they don't have and to see themselves as unfairly deprived. People tend to take for granted many things that make their lives easier—such as electricity and running water—if everyone around them also has these things, and they don't feel happier because of having them. On the other hand, peasants who have never had such conveniences in their villages don't have any reason to think about it.
I would take this point even farther and say that it effectively answers not only the snarky commenter, but also the original question of why autistic people have different levels of satisfaction with their lives. There are some who feel like the urban poor in the surveys, believing that if they weren't autistic they could accomplish more in modern society. Others have an attitude more like the contented peasants, never having thought of themselves or their autistic family members as lacking anything in particular, and taking offense when those who don't share their perspective find fault with their way of life.
When people have different cultural expectations, arguing about how they ought to feel isn't likely to change anyone's point of view. As with any such differences between groups of people, it's often more useful simply to discuss what they feel without being overly judgmental about it, while working toward a more constructive mutual understanding.
Wishing a happy New Year to all!