There's almost never a magic bullet treatment, for any disease, mental or physical.
I have to disagree... If I get strep or pneumonia, they give me a z-pack and bam, it magically goes away. If I have a broken finger, they give me vicodin and bam, I magically don't care about the pain (though yes, the finger itself just takes time to heal). If I have insomnia, they give me ambien and bam, I can magically sleep again. When my knees or hips eventually wear out, they give me new ones and bam, I magically get to walk for another 20-30 years. And keep in mind that many of our "magic bullets" work on a larger scale and longer term scale - Vaccination, water sterilization, sewage treatment, annual physicals, etc.
Even for the things that still tend to kill us, like cancer and heart disease, we have a lot of magic bullets that let us live far, far longer than we would have a century ago. Case in point, we wouldn't have various religiots arguing over their "right" to murder (as in the case from last week) their 10YO daughter by refusing treatment for a 95% survivable form of leukemia. She would simply have died, no moral issues involved.
But for mental diseases, it gets a lot messier. There, I would have to at least partially agree with you. We have plenty of ammo, but precious few we would dare call "magically" effective. Perhaps more like "napalm", where they might get the job done, but with so much collateral damage that you have people going off their meds because the cure sucks almost as much as the symptoms (to give my metaphors a good stir there).
Perhaps more to the point of TFA, I would have to agree with its author. We need to get over this societal PC BS that every sociopath and drooler can, with the right care, grow up and lead a productive life as a rocket surgeon. Some people will never manage more than wiping their own ass, and some people will never grasp why they can't "earn" their living pointing a gun at convenience store clerks. Simple as that. Best for us, and best for them, to keep them off the streets until such time as we can cure "criminal" with a magic bullet - Preferably starting the process before they take a real bullet from an armed victim or a cop or a partner crossed.