My initial reaction is to be very disturbed by such a stigmatizing and negative perspective of anyone with a diagnosed personality disorder.
In the mental health world, it is well understood that one of the most significant signs of health, and most important contributors to our mental health and well-being, is having significant and healthy relationships with others. Social isolation is a sign of ill health, and in such a case, socializing would be one of the most important goals.
Having a diagnosed personality disorders does not suggest the person is abusive just like not having a diagnosed personality disorder does not indicate a person is not abusive. Simply put there is no direct correlation between diagnosed personalities disorders and abuse, except for the possibility that certain types of personality disordered individuals may be more prone to being victims of abuse.
Relationships are not recommended if the individual tends to continuously enter into toxic abusive relationships, unless they have developed enough understanding about their behavioral patterns, to break such a self-destructive pattern.
In short, every premise implied in this question is incorrect.