Provinces want employees for rough, dirty, shitty, or poorly paid jobs. Businesses want to import that labour because it can often be much cheaper, and they may not be able to turn a profit at all without it, so they pressure provincial governments to seek that labour from the feds. The provincial governments are happy to earn support from business leaders, but don’t want to have to think about housing or healthcare for people who move there to fill those jobs.
There are more and more groups now tracking and publishing Labour Market Impact Assessments by local businesses claiming they can’t hire menial workers at $36 an hour or whatever the magic number is to get out of the low wage TFW stream. The abuse of TFW LMIAs is absolutely rampant.