First, this is not discrediting psychiatric evaluation. It's just another article that tries to be controversial but really isn't.
As pointed out in the comments, any professional is very aware of the problems outlined in this article and researchers are working on finding clearer markers for psychiatric diagnoses (see the emerging field of Computational Psychiatry for example)
The one problem I'm familiar with and I'd like to point out is with Major Depressive Disorder (MDD).
MDD is diagnosed if 5 or more symptoms are present for at least 2 weeks. Some of these symptoms are actually in contrast with each other.
This means that is possible for two people to have completely different symptoms but still be diagnosed with the same disorder.
This is shocking.
So it is clear that the problem is with labelling these disorders. That's why researchers, to better understand how the neurological substrate affects the behaviours, are focusing on individual symptoms and only then relate them to categorical differences.
The one problem I'm familiar with and I'd like to point out is with Major Depressive Disorder (MDD). MDD is diagnosed if 5 or more symptoms are present for at least 2 weeks. Some of these symptoms are actually in contrast with each other. This means that is possible for two people to have completely different symptoms but still be diagnosed with the same disorder. This is shocking. So it is clear that the problem is with labelling these disorders. That's why researchers, to better understand how the neurological substrate affects the behaviours, are focusing on individual symptoms and only then relate them to categorical differences.