Most of the consultants I have talked to about this issue (a colleague is going alone) explained that there are indeed people who prefer going on their own, settling down with a job and later on sponsoring their families so they do not burden themselves as well as the Canadian system. If there was a definitive rejection on doing so, CIC would have never given the option of going alone.
Yes - some people do exploit the system in turn creating problems for people such as my colleague who genuinely want to go solo.
Most people who have been rejected for going alone are the ones who declared themselves as single and later CIC found out that they have dependent family. Now that indeed is bad.
