I think you are the one missing the point. People immigrate for different reasons - economic, family, wars, weather etc. Thesame reasons that make people come to Canada is the same reasons that make people go back. If you read the original post by aysi, he wanted to go back home for a year because he has FAMILY PROBLEMS. What's wrong with that??
Myself I came to Canada for economic reasons but that does not mean that I am completely going to forget where I came from. If I so wish, I can decide one day I don't want to live in Canada any more and I want to go back to my home country. What is wrong with that?? I might even decide I don't want to go back to my home country and that I want to go somewhere else... say Australia... for God's sake what is wrong with that?? It's my choice, it is your choice where we all decide to stay at certain times of our lives (AS LONG AS WE DOING IT LEGALLY AND ARE NOT BREAKING THE LAW).
CIC does not have any rules checking motives... unless you are a PR. and that is understandable because the the word says PERMANENT resident so you ought to be permanently here. However, if you meet obligations to be a citizen, CIC CAN NEVER and would NEVER deny you of getting your citizenship. It is the law and Canada is a country of laws. If you don't like the way the law is currently, then try to change it.