The term mature hairline sounds like a cop out to me made up by doctors. Explain if I am wrong here. A mature hairline is considered some slight recession that most men get at a certain age regardless of if they are balding or not. Wouldnt then it follow a NW 7 would simply be a hairline that is more mature then the normal hairline and hence balding would not even exist as a term right?

I do not believe you are understanding the difference between the mature hairline and male pattern baldness (MPB).

Most Caucasians (95%) will have a mature hairline as they “mature” from their teens to twenties, but about half of the men will have genetic balding, otherwise known as androgenic alopecia (AGA) or male pattern baldness (MPB) by the time they reach the age of 50. The term “mature hairline” is not some hype or concocted term, as it does describe what happens as the juvenile (your 12 year old hairline) changes into an adult hairline. Use your eyes at shopping centers and observe men over 30 and you will see just what I am talking about.