Does Chuck Palahniuk teach a life lesson to readers through his novel Fight Club?

This book is full of life lessons, but let's examine just one of them here more closely.
The narrator of this book is mentally ill, and the fact that one side of his personality is incredibly unhappy with his mundane life causes his other personality, Tyler, to develop an increasingly unpredictable and unstable lifestyle to help the narrator deal with this unhappiness. While the narrator cannot be exciting or "feel alive" in his life at work, in his off time he can be as exciting and risky as he wants to be with Tyler. So, what does this mean for readers?
Even without multiple personalities, we often tend to have one part of our lives where we may feel more limited, restricted, or even unhappy than in other areas of our lives. In this particular book the narrator finds this most in his career. This is also a common problem for many adults. Often people find themselves in careers or jobs they are unhappy with but feel unable to leave. This leads them to feel trapped and as if they have no real purpose during those 40+ hours per week—and it could also lead them to want to escape. Healthy ways of escaping might be days off, restful or fun weekends, or vacations. Unfortunately, the narrator escapes into dangerous and risk-taking behavior instead that makes him feel alive because in his work life he feels dead.
Although starting a Fight Club and a Project Mayhem might not be typical of someone looking to take risks outside of work, other behaviors like binge-drinking and abusing drugs may be. These behaviors can be ways for people to relieve stress or escape in unhealthy ways. The narrator's escapes are simply more extreme than what most people would think of.
What this novel teaches readers is that extreme unhappiness should be directly addressed instead of simply avoided. Even if the narrator had not been mentally ill, the message to readers is that gross unhappiness can lead someone to take part in risky and unhealthy activities to make up for the boredom they face in other areas of their lives, and there are very negative consequences when that is the case.