Why do they call a G.E.D a high school equivalent?

I dropped out of high school at 17 and got my G.E.D. I thought it would be the right choice since my dad committed suicide my sophmore year and I changed schools twice because I was tired of people feeling sorry for me but every school I went to people magically found out. So I got my ged. Last summer I decided to join the army so I went to the recruiter and I have been jumping through hoop after hoop after hoop. I was 275 pounds in november and I am down to 230 and at 20% body fat. They are now telling me that I have to go to college... Why in the hell do they call a G.E.D. an equivalent to a high school diploma? It is in NO way close to an equivalent. If anyone is reading this that might want to join the military and are still in high school, DO NOT DROP OUT--- GET YOUR HS DIPLOMA. LIFE WILL BE EASIER AND BETTER ALL TOGETHER.