The program varies from one province to the next, but most of the Canadian provinces are using the model that is based on the belief that intensive intervention, if applied extensively, can eliminate a child's need for services in the future.
So, the model that you feel is inadequate was actually chosen by people. The timeline varies depending on the province, but, in all cases, an extreme amount of care is provided, followed by a total lack of care. However, adolescents and adults need crisis management cells that are extremely flexible, versatile and available as needed. They need this all their lives.
Regardless of whether they are doing very well or very poorly, autistic people need assistance on and off throughout their lives, especially when it comes to work, housing, social duties, such as filling out paperwork, and so on. No type of intensive treatment will help those people dispense with the services as adults.