I can appreciate your viewpoint as it's a common one. On the other hand, some individuals who truly have ADHD and are untreated self-medicate to control their symptoms. I am one of those individuals who self-medicated. I was undx until graduate school.
My brief story: I started drinking coffee at age 11 because it calmed me down. I started smoking cigarettes at age 12 because it also had a calming affect. Both of those are stimulants. In high school I drank a lot and occasionally used MJ. Yes, both of those are depressants but when I was on them, I was calm. I no longer smoke - thank goodness. I barely graduated from high school because of the severity of my ADHD. It took me three years to complete two years of community college because it took all of my cognitive effort just to attend to what I was reading and block out all incoming stimuli, including the slightest of sounds. I went to university and finished up the remaining two years of my undergrad., still undx although I suspected I had ADHD. Finally in graduate school, I was dx and was put on medication. I can't began to tell you what a difference it made. My grades continued to rise and my writing abilities jumped ten-fold. Prior to medication, I couldn't even write one sentence without my mind becoming all jumbled up. Your writing skills are better than mine was going into graduate school. I just got a lot of help from people. My undergraduate degree was in speech and hearing sciences, so I hardly had to write papers. My ADHD was so bad I didn't even know where to put commas. I never had the attention span to learn and things like commas are among the many little details I often missed. I seriously never read one book until I got into college. Then it took so much effort to read even a page.
I no longer truly "need" medication to function but life is much easier on it. I am much different today. I read all the time and my attention span is so much better. I still get "labeled" as the person most likely to lose her keys by other staff members at my school:).
My father and his five brothers are very severe. They have all self-medicated, which is a pretty sad story.
It is true that boys are more identified than girls. I do believe that boys are over identified and girls often are under identified. What your brother went through is sadly common. I worked in a high school as a school psychologist and a lot of the boys stated very similar things. I remember a few stating that they would rather deal with the ADHD then with the side effects of medication.
My father is extremely successful as a car salesman because he is a constant mover. He really can't sit still. It drives me crazy. He has been doing it for 30 years. There are a lot of people who are unmedicated or undx (officially) ADHD who are extremely successful. I think it's great your brother is in football.