My sister, a high school English teacher, immigrated to Canada three years ago. Instigated by her and motived by children's future education, I submitted my own application immediately after her landing in Vancouver. We shared all the details of her three years living in there, laughters and tears, desperation and depression, successes and failures. I am glad to say that my sister has totally pulled herself up from nothing and now she has been enjoying a life that's exactly what she had been longing for.
Many reasons I can imagine that may cause an incessant immigrants exodus. First of all, jumping on the wrong bandwagon lacking of a thorough self understanding. Therefore, they could hardly fit in the whole new environment when they really took a hard look at what they had chosen over their old lifestyles. There is nothing to be gained by pointing fingers if they came back, after all, "there is no place like home", as one old saying goes. There were also such individuals as making money a lot more easily in China than in Canada, so it's quite understandable why they rushed back. One more reason of this common phenomenon I'd still like to add is that the medical systems are completely at odds with one another. Here in China, we seek medical care as soon as we are not feeling good, despite the fact that corruption lingers everywhere with no exception in hospitals; but in Canada, you will have to consult with your family doctor prior to going straight to hospital, as a result, many diseases often heal themselves at the time you are sitting across from a hospital doctor. As for me, I can't tell how long it takes me to get used to the third part of what I stated above, but one thing is for sure that I have overcome the obstacles of the first two parts. I know exactly what I asked from this immigration thing and I have been well prepared for this changing, linguistically, technically, physically and psychologically.
Well, it's good to debate over this issue. We should all be a bit more prudent before rushing into any decision, no matter immigration or something else.