You obviously don't know much about how government works in Canada. Any fees you pay for any service, usually cover only a portion of the cost. If you actually look at all the man-hours and levels of people that are involved in doing something, the real costs are much higher and funded by general taxes. This is true for any fee you pay the government for anything.
You really think $500 in processing fees fully pays for the direct wage, all the benefits, and all the pensions of the people that process an application including the visa officer, medical officers, all their managers, and support staff? Not to mention visa officers travelling to attend interviews in many cases? The total budgets of visa offices do not come close to being self-funded by application fees alone. You would need to be completely clueless or delusional to think so.