Some people consider A Small Place to be an angry book, but we think it's a little more accurate to call it passionate.
Our narrator is certainly willing to rage against the machine, like when she calls the tourist "an ugly human being" (1.5). But she gets equally emotional about the things she loves, like the old Antigua Public Library and the "sound of its quietness" (3.1). Sure, she's angry more often than not, but those emotions are only in response to circumstances. And as the book shows us time and again, those circumstances are not of her making.
If you ask us, people call this book angry because the narrator is so cynical. We never get the sense that she has the solutions to any of Antigua's problems, and that's probably because she thinks those solutions don't exist. In fact, she plainly states that the only thing she wants is for "a way be found to make what happened not have happened" (2.3)—which is impossible. This uncompromising mindset shows a cynicism about the future of Antigua. But given the nation's past, we can't say we really blame her.