In general it is very hard for visitors arriving to claim H&C or it would negate the hard work others do to qualify for economic immigration programs. Yes everyone has their own case but no immigration lawyer would suggest that thais a good way to try and secure PR.
you still generalize! anyone may need compassion because he has humanitarian reasons and it has absolutely nothing to do with status! and I still don't see the connection with the fact of having no luck with the economic programs and a visitor who wants to apply for PR for humanitarian reasons! also a foreign student or a temporary worker could have zero chances to apply for PR through economic programs! and if you think that a visitor has not lived enough time so he does not have good arguments for the establishment ( which represents a factor among several others ) you are wrong! note that the integration is not necessarily based on the duration, there are people who have lived here for years but they don't know anything about life here and about the country, many lived in canada for a long time but they dind't study, didn't work, they did not volunteer, no family or friends etc... many have lived in canada for 4, 5 10 years with work permits or study permits but their application was refused, why? because they didn't have real humanitarian reasons! while other people have applied for PR after a few months or a year of living in Canada but they got a favorable decision, because they had good humanitarian arguments.
Any good lawyer can suggest H&C to his cilent if he judges that he has a situation that deserves compassion.
Applying for permanent residence for humanitarian reasons is not always a tool for people who do not qualify for economic programs, but rather for people who need compassion based on their arguments and of course, each case is different !