alt Hacker NewsThe problem here is that the usual explanation sneaks in multiple rarely stated assumptions.
If Monty knows the door with the prize and is aiming for the game to continue, then you should switch. (This is the usual argument.)
If Monty doesn't know where the prize is, then you learned nothing. (Monty's result was luck, and he can't impart information that he doesn't have.)
If Monty knows where the prize is and wants you to lose, absolutely don't switch. (Monty will only drag the game out as a way to try to make you lose.)
The reasoning behind these statements is completely solid, and there are no hidden assumptions being snuck in.
I think, canonically, Monty always knows where the prize is, and will always eliminate all doors except for one, and will never eliminate a door with the prize, and will always give you a choice to switch. There's no room for Monty's motivation.