Sorry to hear for those who got rejected. Perhaps i can help explain one aspect of the recent trend of high rejection rate for student visa's.
Luck plays a huge role in these situations when you consider people who have no chance of getting a visa actually end up getting it. But what you can do is prepare for the worse and don't get overconfident when applying.
You have to satisfy them that you are going there for genuine reasons to study, which is very hard to do especially if you come from Punjab since punjab region is well known and tops in every kind of immigration fraud in canada. Also, a huge majority of students from punjab end up never going back even after everything fails to get PR, marriage being the last step. In comparison, students from other asian countries like china, korea etc will almost always return back to their countries. Bright chinese students are actually sponsored by their state govts to study in Canada and bring the education and english language experience back to their country to benefit them. India, probably does not care.
Canada is also the *new* Australia as an education destination for students from India (asians have been coming here for school for a long time). And in a way, they want to attract and retain top talent. I don't think you would see many rejections for those going for engineering/ technical degree programs in *reputable* universities. Diploma programs, thousands graduate every year and sort of share the same fate of getting nowhere. I know a handful of guys who graduated from business management programs (even a few with MBA's) who got PR and everything and ended up as truck drivers. Why you may ask, because the purpose of their education was just that, get PR and make quick money. Sure they are paying taxes but the intentions that the govt gave them PR with, hoping they would contribute to the skilled worker shortage is not getting met. Anybody can drive a truck, you dont need a business education for that and the FSW and TPW programs are there to address these labor shortages.
So they are learning from their experiences and changing things accordingly, scrutinizing applicants more closely and making it harder. Same thing for PNP's where the idea is to grant PR so skilled people (as per their definition of skilled) can help improve the economy of the province they applied in. but what ends up happening is after getting the PR, people just get up and move to toronto or vancouver. So PNP programs of smaller provinces suffer and eventually become strict (case in point Nova Scotia) and Ontario and BC PNP's are harder to begin with.
I'm also sure there is probably an annual quota of student visa's from each country and it can be a draw as to who gets one of the limited approvals. So if you get rejected, this is not the end of life. Rabb jo karda changa hi karda and in the long run, it all makes sense. If you really want to go abroad for education, Canada is not the only country. Break free from traditional US, Canada, UK, australia and look elsewhere (such as in europe).
Rab Rakha!