Yes but they're definitely enabled and encouraged by the Canadian governments policies. For example - allowing international students to work 40 hours a week outside campus. That's ridiculous. It's they're deliberately creating legal loopholes to be exploited. When I was an international graduate student in the US, I was allowed to work no more than 20 hours per week and only on campus, so international students never took away local blue collar jobs like in Canada
Yes, a combination of things, including federal policies.
I'd also draw attention to the provincial governments: they allowed the colleges in particular to just go wild in beefing up international students, with a lot of dubious programs. The difference can be seen with some provinces and colleges/areas having gone crazier than others. You can also tell they believe/know it's short term gold rush behaviour because they didn't think about or even plan to build housing at all.
In Ontario, universities and colleges (or at least people in/close to them) also draw attention to the tuition freeze for domestic students that was brought in by current government. Effectively forced them to go to international students to help cover rising costs, but those programs have costs on their own. The universities have been hurt but haven't gone as nuts as the colleges. Some grew their enrollment by just outrageous amounts in only a few years.
For colleges in Ontario - and some of the programs they adopted in cooperation with some private sector players - you can see it in the political donations.
The feds issued the visas. But the provinces - some of them anyway - were absolutely CLAMORING for more more moar visas. The line to corruption at the provincial level is pretty damn clear.