Why would somebody with aspergers be branded a narcissist?

So I have been seeing this a few times in my life. A person with aspergers sometimes gets misunderstood and labeled as bad person, narcissist or psychopath?

Why do you think this happens? Often times, person with aspergers is left chronically pondering what is wrong with them. Feeling shame, guilt and miserable. Meanwhile some actually narcisstic or psychopathic people run companies and funcion well enough.