No.
Some conditions are overdiagnosed, and there is a too-cozy relationship between medicine and pharma that is disturbing to many of us.
However, to make a diagnosis based on Diagnostic and Statistical Manual (DSM) criteria almost without exception (one exception is for bipolar II disorder) require that symptoms (and several symptoms are required usually for any given disorder) must cause significant impact on one's lives, eg,
"...sufficiently severe to cause marked impairment in social or occupational functioning or to necessitate hospitalization to prevent harm to self or others, or there are psychotic features."
or
"...symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning."
EDIT: (based on your own edit) - reserving diagnosis and treatment just to those at risk for self- or other-harm is going to harm many suffering people. I don't think you understand what depression really is. It's not caffeine withdrawal or the flu. Even when no suicidal ideation is present, it's a serious disease with real costs to the individual and to society, just as real as cancer.
Beyond depression, I think you'd agree that even in the absence of harmful behavior or ideation, people who experience auditory hallucinations in the course of depression, or OCD sufferers who are unable to work because they must wash their hands hundreds of times a day, or who have PTSD triggered simply by backfiring engines, or who have dozens of other DSM diagnoses, all have legitimate illnesses that deserve much more than the terrible, stigmatizing suggestion that their illnesses somehow are not real.