well, Yeah visa officer knows but still he cant allow everyone to enter their country.
I disagree to you because having alot of land does not mean they want to fill it. I know its a Immigration friendly country but still Canada dont want too many people. they have set a limit and facing a lot of problems as they allowed too many in their country and they are facing hurdles to maintain it.
when you allow too many people in your country you have to give them health, job, and other basic facilities. and there are thousands of people recently immigrate to Canada and looking for job. they all contribute to overall unemployment rate. its not all about filling place actually most of the Canadian population living just beside US border coz northern area of Canada is simply out of account. almost impossible to live there. its not like US where every state is populated. and they dont want canada to make it like US.
secondly they will check every students home ties and if they feel his only focus is to secure entry via study they will refuse him even though if he is going for PHD. they highly appreciate if the student wants to come back. If you see IDRC, commonwealth or other scholarships, they signed you a bond that the you will leave Canada after research. and IDRC give funding to only those students who will have research topic relating to his home country.
so guys you must show strong home ties, If neem hasnot show any ties and got visa its his luck but dont follow him he must have some very strong points in his file so that VO grant him visa. there are three important factors any visa officer looks before granting study visa
1. genuine student/admission
2. financial matter
3. home ties