Of all the paths to immigration, international students are the most beneficial to Canada. You bring in young, ambitious, smart people. They are often subsidized by their parents, so you have net capital importation. You get to train them however you want. They help build up Canadian universities as truly world class research and innovation centres. Even if they leave Canada, they become important cultural ambassadors and business contacts throughout the world.
Limiting this stream is ridiculously stupid. We do have societal problems, like housing and healthcare shortages. Guess what, many of those international students want to study to become healthcare professionals. And when it comes to housing, well motherfucker just build.