I agree. The problem is that Borderline Personality Disorder is not a desirable diagnosis. There is a great deal of stigma attached to it and many clinicians won't treat it because patients with BPD can wreak havoc in their practices. It is possible that people with BPD seek out a bipolar diagnosis because it seems more "legitimate" to them and they think they'll be treated better by clinicians. The problem is taking meds you don't need for a disorder you don't have is a serious health problem. The responsibility falls on psychiatrists to take good histories and be clued in to patients' inconsistent symptom reporting.