From farm to pharmaceutical - why are we treated alike!!

I understand that our medical field from the time of it's conception was just a creation of testing, not of actual treatment.
There is an excellent book titled "Murder by Injection" PDF versions are available online to tell you the corrupt beginnings of the American Medical Association and the "research" on pharmaceuticals.
I was raised and taught that plants are living things. Some need a lot of sun and dry soil while others needed shade and damp conditions. Animals came in a variety of species and just because it was the same "animal" the species or type of that animal didn't always get the same treatment as another.
How is it that the medical field has an "Average" scale that every human must fit into to????
I am way below average when it comes to the medical requirement for everything.
My weight is on the very low end of the scale, even though most of my diet is on the do NOT eat list.
My blood pressure is so low that there are times that even the Red Cross tech thought that I should be dead.
My heart rate doesn't even rate on their scale, so I'm just below the line on every subject.
During all of the research that they have done and all the money spent since the beginning of medical research has anyone ever challenged the fact that there may be different species of human beings and that we all just not the same and should not be treated the same??
Has anyone else thought about this...