Assholish? Snarky, maybe, sarcastic, sure. But assholish? Depends on context. I suppose I can’t imagine my mother talking to me like that either. But my dad? Hell yeah. Not those exact words, but the main thrust that amounts to, “We can have that just as soon as you’re ready to pay for it because money doesn’t grow on trees, and even if it did I could find better uses for it, lol.”
I’ve already expressed my position on “mcdondald’s money” as an expression (I’m pretty much aligned with actualliberalnotoneofthose). It seems to me that the real cultural divide is not “who’s ever heard of McDonald’s money?” (which is an expression about “____ money,” not unique to McDonald’s), but rather “who had a sarcastic/snarky parent who would come up with sarcastic, perhaps even borderline mean, ways to say no?” Like the mother in American Beauty:
“Mom, do we always have to listen to this elevator music?”
“No, we don’t. As soon as you’ve prepared a nutritious yet savory meal that I’m about to eat, you can listen to whatever you like.”