I hate to bring up an analogy, but go to any weight lifting forum and see the debates about the apparently billion different lifting routines and their effectiveness. Inevitably, most of the “medically” studious debaters do not have the physiques worth pursuing, but do have excellent arguements and persuasive powers. Not to sound like Rocky, but in the end with lifting persistence and consistency pays off more than any other factor.
I believe PE is the same. Why do we need to worry about the medical reasons that are likely to change over time when it works? Eugene Sandow did not question the value of heavy resistance training to his strength, even though it took nearly one hundred years for some scientists to articulate various protein synthesis into muscle reactions and such. Do you want to wait one hundred years for a larger penis?