Understood. However, I think the commenter might have been making the point that we expect a certain degree of variability in personality traits, and that class

Understood. However, I think the commenter might have been making the point that we expect a certain degree of variability in personality traits, and that classifying such a large percentage of the population as having a disorder where the diagnostic criteria are somewhat vague makes him or her skeptical about the existence of the disorder. A person might also reasonably argue that hyperactivity and a broad attention span are advantageous in certain environments, just not the environments where we tend to educate children. Contrast this with myopia and colorblindness, where the diagnosis and disadvantages in every environment are unequivocal. I don't claim this myself, I just wanted to clarify a possible point of difference.