i dont know this for sure, but my understanding is that, since we are applying study permit, the intent should focus on studying while not others, including pr.
if you applied study permit but in order to get pr at the end, firstly, it would level up the risk of illegal immigrants anyway ( yes you may go back if you cannot get a valid work permit or pr after graduation, but from a macro demographic perspective, there obviously will be someone overstaying without legal status). secondly, a pr oriented study permit applicant is more likely to study not for their interest or career development, and this leads to a poor education outcome, which also occupies the limited resources for those who really intent to study.
and besides, since we are neither pr nor citizens of canada, it is not our right to demand a study permit from ircc, but instead, it is the right of ircc to decide if we are allowed to enter into canada to study or not.