I do agree with what you're saying about severity. For something like seasonal affection disorder or a moderate depression, you'll probably not want to reach for SSRIs etc as the first cause of action, much like a gastric bypass isn't the right tool for someone who is slightly overweight. But it is a good tool to have for severe cases, and the idea of "it's not real weightloss if you didn't achieve it through power of will alone" is damaging.