Hairs on the front of the head and back of the head are the same, there are no extra sensitive hair follicles or any of that nonsense. DHT only becomes inflammatory in a hypoxic environment (low oxygen/ blood flow).. The front / top of the scalp gets less oxygen over time, either from arterial plaque or calcification of the arteries. When this happens DHT initiates an inflammatory response when there is low oxygen. DHT otherwise triggers an increase in hair growth. The capillaries are very weak at the top of the head and easily compromised for certain individuals with bad genetics.
Lowering DHT is like an indirect way of dealing with baldness. YA it might solve the problem but doesn't help the root cause. And DHT will be a lot higher if you have higher estrogen levels. (not excercising, eating junk food, excess toxins like BPA)
A lot of people will dispute this because of the mainstream bullshit, but I've done my fair amount of research on the subject.