Well at least a few in every government have proven that they are incapable of making wise decisions. Laying it out clearly avoids the inevitable "i made a mistake, I didn't realize I wasn't supposed to do that". If people setting the rules for others can't decide to follow them based on smarts, common decency and moral authority, maybe a substantial salary hit and high probability of your political career being ended is sufficient motivation to play along.
Political career: At $115,000 to $165,000 a competent desirable person could do better than that in the private sector. Add to the MPP salary a bit of a slush fund and perks. Then down the road there are other enticements and a pension deluxe.
If the person was truly in it for the betterment of his / her constituents it would be like a parent / child situation where it isn't my time vs your time.
You do what you have to do.