Dr Proctor:
Antiandrogens are often poorly-effective alone...In fact, from the clincal experience with, e.g., treatment of prostate cancer, it seems that even complete castration doesn't work much better in balding than these antiandrogens...The implication is that we may have already reached the limits of what can be obtained with antiandrogens in balding.
Possible explaination: Male hormones only initiate balding. Further, whatever hormones do seems to be mostly irreversible. The main damage to the hair follicle seems to be done by other factors, especially immunological.