No, as a parent of a child with ADHD, I can tell you that it's not.
It is overdiagnosed, and it is over medicated. But it's NOT BS.
My son is now 18 and still deals with some issues of his ADHD. We stopped meds way back when he hit puberty and, if we had it to do over, would probably not have done the meds at all.
But the condition is real.
The condition, as you call it, is a subjective one; did you ever ask your son the whole time you were pulling out your hair trying to figure out why he wasn’t just like all his behaved friends what he thought about the treatment?
Has he ever asked you why you didn’t accept him the way he was?