A two-year process is a lengthy one. For most of the people who come to Canada, outside of the refugee status claim process, there are other things that are important. For example, they must find a job or have access to employment assistance agencies or organizations. It is very difficult for a person to just stay in limbo and to not have access to such services, because he or she does not have permanent residency or Canadian citizenship. The individual cannot make ends meet financially, and it is a very difficult situation to find oneself in.
Some immigrants who come to Canada are skilled workers. They could quickly integrate the job market. It is a loss for Canada to leave these people on the sidelines for two years, to then ask them outright to retrain so as to be able to be full-fledged partners within the system. Two years is a rather long time to leave someone on the sidelines.
That is just one example. It is difficult for a person who is barely surviving financially to fit into Canadian society.