I have to agree with you in general.
Something else I've wondered about is why do we have so many people on antidepressants. If anything I suspect that depression might actually be underdiagnosed, but we really have no idea what it actually is.
When you have substantial percentages of the population requiring a medical treatment you have to start asking why. Have so many people always been depressed, or is this something new? If it is new, what is the cause?
Sometimes I wonder if the brain has a natural feedback loop that leads to depression. I tend to find myself feeling down when I should probably feel the most comfortable. If something bad happens or something good happens I tend to snap out of it. However, if everything is going just fine and I'm in some kind of routine, I start to feel less and less satisfied with it. Perhaps there is some survival instinct that just makes us feel continuously uncomfortable if we aren't improving our living conditions/etc.