spacedmountain
The condition is usually defined by having an impairment in at least two environments (ie school, home, work, sports teams). 'Impairment' is obviously subjective, but implies something more than simply being bored. Playing a game in a boring meeting probably isn't ADHD. Being unable to focus for more than a few minutes in _any_ meeting is a stronger sign, and could really make it harder.
On diagnosis rates - in most countries its 2-5% (>10% of children in the USA..). That is about 2 standard deviations from an 'average' person, which can actually be quite a difference. For comparison, a 'genius' is someone who scores in the top 2% of an IQ test. Economic elite are '1%-ers'. I'd agree that there is a continiuous spectrum, and also that it is mis/over-diagnosed in a considerable number of cases. I think it is this over-treatment that you are questioning, but lets be cautious to not add to the stigma around legitmate cases of the condition.
I'd agree often the challange is between individual and their environment - although often 'enviroment' includes people around them. Often the environment is hard to change - do the 95% change to accomodate 5%? There is advice for careers that people with ADHD tend to be better at - sales, entrepreneurship, and medicine for their fast-pace and energy, or jobs like the military where there is a lot of structure.
I think its more complex than saying exercise would reduce diagnosis or medication rates. In particular, if exercise alone 'cures' ADHD, it is likely a mild or mis-diagnosed case. In my own experiance, exercise (as well as sleep and diet) do affect symptoms, but don't eliminate them.
I'm not sure ADHD would have a better time for lifestyles. People with ADHD would always be a minority, and probably perceived as odd by others. Organisation and focus have always been useful traits - but also creativity and adventurousness have led to rewards as well (but also risk).
A better analogy I've heard is ADHD is like a Ferrari engine in a golf cart. There's loads of power and energy, but the steering and brakes struggle to keep up.
People with ADHD can motivate just fine on things that stimulate them - and have even reported 'hyperfocus', a trance-like state of emersion in something. The problem is things that are not stimulating become very challanging or even impossible. This is why bills, appointment, rules, and chores can be so difficult for ADHD people to commit to. 'Normal Type' people may find misery in these sorts of tasks, but they are able to motivate themselves to complete them - and the tasks generally don't take that long for them.
A good way I've heard ADHD described is that people with the condition have no percetiption of time. If stimulated, its easy for them to loose track of how much time has passed - even forgetting to eat or sleep. If unstimulated, the misery seems to be never-ending, even if it would only take a short time to complete if the person applied themselves.
As an example: Michael Phelps (who has the condition) has been very able to motivate himself to practice swimming. Swimming at his level is a very tedious sport, requiring five or more hours a day in a pool staring at the black line on the bottom.
I've personally found sport (swimming and extreme) to be helpful in managing ADHD, both while doing the activity and maybe for a day or two afterwards. Also as a motivator before hand to get through tasks I find miserable to give some time for the activity.
Additionally, people who may seem to have ADHD may in fact have OCD, anxiety, depression, or other disorders. And vice versa. Or they may have a combination of one or more of these with ADHD.
I do think there is a component of ADHD treatment that is trying to 'fit in' to a society that doesn't think the same way the person with ADHD does. But there are big impacts on people's lives independent of society. And its not easy to always be "different", disruptive, and/or inattentive to people around you.