In the 70s and 80s, kids with disabilities weren't placed in the regular rclassroom. In ths 70s and 80s, relative to the cost of education system operation, funding was superior. 

There is no 'payoff', either; this is something that was negotiated at a bargaining table, in lieu of higher wages. BC teachers have the lowest average salary for the profession in the nation, exacerbated by the lowest starting salary outside of Quebec (which has lower standards).