This book basically sums up the problem with psychiatry, social work, law and welfare. Essentially people have to be sick in order for someone to treat them, ergo, people must be invalidated in order for someone to gain employment as a "profesional".
Law essentially becomes the domain of people that use their socially created "authority" to impose judgement or justice upon those that they deem undesireable to the community. Rather than becoming a means for resolution of disputes, the system gets used to invalidate people so a profesional workforce can maintain class construction.
Without a seperate system of experts people would gain autonomy over their own lives, such as birth, death, care, etc. Most incidences of these categories have been taken over by a medical abstraction based system that often creates more iatrogenic outcomes. People become overmedicalized, lose authority over their lives and are forced through law and medicine to turn over responsibility of their lives to experts more capable of treating "diseases" when in my opinion the whole enterprise seems a reentrenchment of "religious" control with "scientific" control, aka eugenics.
These professionals create needs in the people that gain degrees in these disabling professions to legislate political outcomes not, I repeat, not based on sound scientific basis, but mere professional or moral judgement, a modern version would be drugging of children on psychiatric drugs, redefining most behaviors of youth as abnormal, which come to represent a moral movement instead of a scientific movement to control people, but using the cover of science to persuade people to submit. By controlling people through these means they gain employment, so it benefits these professionals to lobby politically and religiously to reconstruct society around professions that cannot fix the problems of society, these professionals become disillusioned and then eventually come to either disbelieve their work or become more fervent as a religious believer might in such work causing further harm to more people in the hope that the right treatment maybe just around the corner so to speak. Those that don't continue to follow this line of thinking eventually have to be retrained.
Since these professions don't lead to solutions to socio-economic problems they tend to disable both the person that has been forced to give over their autonomy and the person in the profession that wants to help people, but has failed to find a solution. In law they simply exclude or attempt to exclude the public from the legal process and tend to use mystical techniques to overide the rational understandings of those excluded, one example being the dialogue and legal construction of language or abstraction of "law".
Since people construct these mystifications on purpose to enable employment most jobs tend to not actually function in a way seperate from moral implications. Also, people in society tend to construct the socially accepted mystifications as accepted fact and further erode their own autonomy as well as being propagandized through media constructions.
Discipline & Punish: The Birth of the Prison and Deleuze and Guattari's Anti-Oedipus have further elaborated upon how society constructs a kind of schizophrenia in capitalism, which I think complements this short work, they also refer to Illich as well. So I think the disabling should not continue to go on, we need to bring up these issues of power and the manner that it has been distributed and will be in the future, otherwise more graduates of psychology, sociology,law, medicine, etc, will continue to find themselves disillusioned and at times causing more harm than helping those with whom they cannot fix, due to the loss of autonomy that appears through the creation of disease where none used to exist merely for pharmeceutical profits or to maintain social positions of power(as this book implicates), or to gain power through taking such away from the poor whom would otherwise protest such conditions if they were conscious of the outcomes.
Some other reading as well might be such as...
Overdosed America: The Broken Promise of American Medicine (P.S.)
Our Right to Drugs: The Case for a Free Market
The Healing Brain: Breakthrough Discoveries About How the Brain Keeps Us Healthy
Toxic Psychiatry: Why Therapy, Empathy and Love Must Replace the Drugs, Electroshock, and Biochemical Theories of the "New Psychiatry"
The Future and Its Enemies: The Growing Conflict Over Creativity, Enterprise, and Progress