Kids abuse them all the time. You go to any college in the country and you will find a mass amount of kids who use them to study. Kids sell them. Kids snort them. They are slung around big time during finals.
I agree that there isn't much wrong with the drug if not abused. That said, the more you use them daily the less they will work. The more you will seem to need. Abusing them isn't always on purpose. They can be terribly addicting.
Caffeine is a fairly safe drug, but you can abuse it. Too much of it isn't very good for you. You go a year with having a couple cups of coffee each day and you will feel awkward on a morning where you don't.