here's why you should follow that whim; because your players asked you for it. what else are we here for?
and I mean, if it has never happened to you, maybe it'll never happen, and you won't have to learn anything new.
I get what you're trying to say with "plundering plot points and tropes," but you are unequivocally wrong. a story is a living thing, and the play is the pumping of the blood. plot points and tropes cannot be plundered, and those are but the components of a story to begin with. the story matters. the gold and treasure may go into a fictional economy, but I have never heard of it as a system mattering aside from fiat. if there's a game out there concerned with GDP and the actual flow of goods, I will retract my criticism.
and I mean, it doesn't need to matter. if all you want is for players to get lots of money to buy the things they like, there's no reason why you have to calculate deficits to determine this quarter's sales tax.
finally, being able to inhabit a character's mind and being aware of tropes, clichés, and other narrative conventions are not mutually-exclusive positions.