Knowing one's type gives insight into one's motives, behaviors and interactions with others. The MBTI is unlike many other psychological instruments in that it is not an assessment of mental health, intelligence, or unhealthy personality types or patterns. The common psychological instrument may tell you, among other things, where you are deficient, lacking or disturbed. It is not possible to have an MBTI result that is bad or unhealthy. It does not measure amounts of personality traits or quantities of thought or behavior.
Most psychological instruments report high or low amounts of a good or bad trait.
The MBTI sorts personalities into different types that are qualitatively different. Just as apples are different than oranges, one personality type is different from other types. It does not compare your results to that of other individuals. Most psychological test evaluate you by comparing you to some normal or pathological standard. With the MBTI your responses are the only values used to indicate your psychological type.