Nice article (in that it is concise, direct, and written at a relatively accessible level)--but they set up a strawman and beat it to death.
Why not also chastize companies whose ads imply that GERD might be a PPI "deficiency"? Or high cholesterol a "statin deficiency"? Is sepsis a "penicillin deficiency"? If serotonin-active agents improve depressive symptoms, it does not automatically imply that we believe that serotonin is "deficient". Similar articles could be written about the "dopamine hypoothesis" for schizophrenia--a useful generalization at one time, but hardly a complete picture of the disease.
I've never seen direct-to-consumer advertising that claims that "Depression is a serotonin deficiency". Nor have any of the drug reps I see suggested that an SSRI is more effective than a TCA for depression. I've always hated the term "chemical imbalance" because it does rather imply that we can "test the chemicals" and rebalance them somehow--but to the lay public, who are also receiving social messages that their depression is a moral failing, "stress", or something that they can "just snap out of", the term does at least try to put the locus of the disease on the organ of the brain.
And no, I am not "medicalizing unhappiness" either--as psychiatrists you should learn that pharmacological therapies need to be aimed at specific target symptoms. There are specific neurovegetative signs of depression that go along with the sad mood--and these do respond to serotonergic and noradrenergic agents.