It implies they are just in need of having their thinking straightened out. It is like talking to a diabetic to lower their blood sugar. Clear grounds for malpractice. I have all my patients in therapy because it gives them another way to get some better. I also do not mind if they try meditation, acupuncture, vitamins, whatever, as long as they are doing what is known to work.
Medications work without question.
Not using them in a patient with BPD is a horrific transference issue by the therapist at least or severe narcissism at worse.