Not every disorder has a double-sided spectrum of behavior. What's the opposite of Bipolar?
I don't doubt that diagnosis is hard and error-prone, and I don't think any honest scientist claims they have firm explanations for every aspect of ADHD and its treatments. It's an ongoing field of research.
But 70 - 80% of children quickly show improvements in response to stimulant therapy very quickly. That's worth a try for such a debilitating condition that sees a third of its patients drop out of high school and 5 - 10% graduate college at all. ADHD's heritability is insanely high at ~80%. None of your tenuous data-free assertions really changes the good science that has been established. We're not talking about controversial stuff here like SSRIs that barely beats placebo. You're going to have to do more than poke at some gaps to twist ADHD into the wholly different "social construct" theory you have even less actual evidence for.
[1] https://www.sciencedaily.com/releases/2008/08/080811195643.h...