I have a 12 year old son on ADHD medication. When he was very young, it became clear that he was very impulsive. A constant chatterbox, a flurry of motion, etc. While he seemed mature enough we held him back a year before starting Kindergarten. He struggled in his first several years of school. The teacher's praised him for his brightness but he could not complete any tasks asked of him - which was true as well for his home behavior. That being said, I was very resistant to diagnosing him with ADHD. Not my kid, we're just not doing the right thing yet! We live near a teaching college and were lucky to have access to medical doctors and child psychologists. My wife is a nurse completing her PhD and studied the literature associatetd with ADHD and we finally came to a conclusion to try a low dose concerta (similar or a form a ritalin). For the last 3 years he has scored better than 99% of his Iowa classmates (culmulatively) on standardized test (Iowa Basic Skills). He is a voracious reader (I think he has read every Redwall book, Harry Potter...) and has a incredible memory. Without his medication he still cannot be expected to brush his teeth in the morning without multiple interventions and threats of punishment. So for me, the medication gives him a chance to exercise his potential. He is not a zombie though will be perfectly happy to sit and read. He is a social kid, plays sports and excels at school. His medication hasn't "fixed" him but it does give him a better chance at accomplishing his goals. We have been working with him to develop strategies to help him improve his focus.
The biggest problem I see is that ADHD is a spectrum of conditions. Most kids don't fit perfectly into an easy diagnosis. My son is very implusive but not aggressive. He has a high functioning intellect, but he is not asocial. So every kids is somewhat of a puzzle. Since you can't test medication on children doctors tend to do it in the field. The criticism should be placed on the parents and doctors who rush to conclusions for easy and quick answers. It takes a lot of time and frankly a lot of parents don't have that capacity and our (US) medical system doesn't promote it much either. To say that kids need a smack on the rump and make them play outside is to not really understand what some parents and children go through.