Life is tough and many people, possibly most, want to be told that it's not really tough, it's just that you're special which makes it harder for you and this pill and less work/hardship will solve your problem.
It's why the USA is filled with people addicted to and completely anesthetized by various prescription drugs.
Sure, real depression actually exists. But it's rare and I suspect the over-diagnosis we're seeing is more damaging by removing people from active and productive lives than lack of diagnosis.
When last did you hear a doctor tell someone to get regular sleep, eat well, get some exercise and face up the the challenges they're presented?