It's good to hear of cases in which people stop their psychotropic medication without difficulties. It's pretty much the same sorts of patterns seen when people go cold turkey on alcohol and non-prescription (i.e., illicit) drugs: Unknown numbers of people require close medical follow-up (e.g., medical detoxification), other people do not. A host of variables make a huge difference; these include: duration of use and dose (the longer the medication has been used and the higher the prescribed dose, the harder to stop it); support and followup (if either of these are lacking, the course of withdrawal can become unmanageable); physical constitution (e.g., when an individual's overall physical health is compromised as say in being significantly below their ideal Body Mass Index (BMI), the effects of medication can be far more potent than if they were at their ideal BMI. In extremely rare instances under these circumstances people still do manage to stop the medication and go cold turkey successfully.
Drug companies and prescribing physicians are required by law in most Western countries to provide accurate up-to-date information to consumers on clinical researched side effects and advice on safe discontinuation. It has been my experience working for a number of years in a community mental health service that if consumers have been informed of the relevant information and guided through the process, difficulties associated with both use of and stopping the medication are much less problematic.