Well the author is certainly privileged to not have to think about his own mental health very much, considering who he is and what he does for a living.
The real thing that's happening with mental health in the US and probably the UK is that people aren't so much deciding that their personal problems are diagnosable psychiatric conditions as they are deciding that they would like to become mentally healthier and are seeking help. And the medical profession, being ill-equipped to actually provide a means to change, is turning to psychiatric medicines to control what are essentially patterns of thinking and being. At the gym it would be like people seeking to become better and instead of receiving personal training they would be given steroids.
I was one of those people who wanted to change how I thought about things and how I acted. And so I sought therapy not necessarily because I had a clinical disorder, but because there were a lot of probably sub-clinical issues I was having with my thinking, and having someone rational and well-trained helped me change my thinking and my behavior so it was no longer causing problems for me. Frankly I was nearing a meltdown of some sort.
It's not the same as needing psychiatric care for a personality disorder or for Schizophrenia or for any number of treatable, identifiable psychiatric disorders. But he's standing up this straw man that people like me are just wimps and they just need to suck it up and have a cup of tea or something. It's pretty patronizing.