It is not that hard to understand. We all take risks every day and some of us have a higher risk/reward tolerance than others. Is skydiving something you would do? What about bungy jumping? Many foreigners do not understand the American preoccupation with owning guns; how many people are killed by handguns in the U.S. every year? I am sure there are NRA members on getbig. Have you ever done recreational drugs? Rode in a car without a seatbelt? The list is endless.
I am not saying getting huge and risking your life for the sake of doing so make sense, but it is not unlike many other risks we all engage in. 
Bay you cannot compare skydiving with the usage of drugs - of course we are all gamble with our health - hell eating a burger could kill you these days depending on were you buy it from.
As much as everybody is trying to deny it we all know for a fact that it CANNOT be a good idea to abuse a foreign chemical substance, you don't need to be a mential giant to understand
that taking I dunno insulin unless you are a diabetic cannot by any way or form be good for you.
Dont get me wrong I understand you and half way agree with you, but I personaly find it incredible stupid to abuse chemical substances like some of these guys do, only for the reason to
look different, and mind you its not just the odd weirdo its being used widely around the world.
I don't know I have a hard time putting it into words