Canada is a free country and obviously no one can ever stop its citizens, born or naturalized, from leaving the country. So it's not mobility rights that the opposition of "Canadian of Convenience" is trying to tackle. It seems lots of posters in this thread is missing this: they're trying to stop, or at least make it extremely difficult for potential Canadian of Convenience to get citizenship in the first place. This is why they increased the physical residence requirement in the previous citizenship bill, as well as the "intend to reside" clause.
The question is: who is Canadian of convenience?
If someone comes to Canada and gets a citizenship cannot find happiness and leaves should not be termed as a Canadian of Convenience. Someone comes to Canada with a dream; if he or she finds the dream cannot be achieved, let them decide what they think is good for them. Why someone would bother with their personal choice before and after! Shattered dreams and waste of talent cost more than so called benefit one gets. Don’t blame the ones who go through mental tortures, humiliation, and inferiority complex for not being able to do what they had planned before or were trained for. Even people are taking US citizenship and moving to Canada or elsewhere if they don’t find what they want there. I don’t hear anyone shouting on the other side.
One small example: I ordered an airport limousine few months before, the driver was a gentleman may be of between 55-60 years and happened to be a senior engineer of General Electric (GE) in Libya with work experience in Europe and the USA. He and his family is living here, contributing to the economy and also receiving the benefit what everyone is entitled to. My personal advice for him was to use his talent anywhere in the world he could, sometimes people can invent the things whole human kind can benefit. I don’t term him a Canadian of Convenience if he leaves Canada, because he is still willing to contribute in Canada in a level below than his qualification/experience and also for less money than he is entitled to.
In my opinion Canadian of Convenience is the one who misuses the system to come here (make fraud claims for immigration, enters with fake work permit or fake marriage or made up asylum cases) and once established, “contributes” to the economy by making money through unethical practices, criminal practices, exploiting legal systems and using loopholes in the systems even though still lives in Canada. They feel only the space inside their “four wall” the home and don’t think Canada as a home. They may portray themselves as true Canadians, but don’t respect the law and the country in reality. These are the dangerous problems for Canada in long run than a person who merely crosses the border for a better life.
But if we are talking about frauds, they should be punished during processing or any time in future.