They aren't nefarious in cartoonish villain type ways, they are nefarious in very boring and predictable human ways. Control over others, greed, politics, laziness, burnout, ignorance, ego and arrogance, narcissism. One of the posters in this thread is trying to handwave it all away "oh we do our best and and the bad stuff if because we are worried about liability". But the problems are much deeper than that and the institution itself is fundamentally flawed to the point that it's generally not a good idea to place yourself or loved ones under the care of a psychiatrist and more of a last resort.