Why would that be a reason not to trust this field? I could understand this argument more if you were talking about a specific disorder being diagnosable in eve

Why would that be a reason not to trust this field? I could understand this argument more if you were talking about a specific disorder being diagnosable in every person on earth--because how is that a disorder if it's the norm?--but you're very much not saying that. As an example, would you consider dentistry untrustworthy as a whole just because dentists would diagnose almost every person with a cavity or some form of tooth or gum damage at some point in their lives?