Think about Miles’s statement in Tuck Everlasting: “It’s no good hiding yourself away, like Pa and lots of other people. And it’s no good just thinking of your own pleasure, either. People got to do something useful if they’re going to take up space in this world.” What does this tell you about Miles’s view of the Tucks' situation?

The passage tells us that Miles wants to do something meaningful with his life, despite what he considers the "curse" of immortality.
To Miles, hiding away to protect others is fine up to a certain point. After all, if everyone could live forever, the world would be a very crowded place. Also, not everyone will share the same moral values in life. The idea of criminals living for eternity doesn't bear thinking about.
This is why Miles and his family continue to hide from the general populace. They don't want anyone else to discover the spring and drink from it. However, Miles becomes restless. He tells Winnie that he used to have a wife and two children. When his wife discovered that he would never grow old (and die), she took their children and left him.
In the passage you quoted, Miles voices his dissatisfaction with life and the way he must live (away from the public). He believes that the way his parents have chosen to live is dysfunctional in many respects.
Because all of them live secluded lives, they can never form meaningful relationships with anyone outside of the family. Additionally, there is little to no opportunity for any of them to engage in worthwhile pursuits.
This is how Miles looks at it: despite his immortality, he can't use it in any way to help anyone. In other words, there isn't anything he can do to make the world a better place. His "gift" frustrates him rather than makes him happy.