Mario and coins essentially go hand in hand. Although one can argue that they aren’t the most crucial element to the series, the games certainly wouldn’t be the same without them. So, could you imagine coins being replaced with fruit?
Shigeru Miyamoto revealed that this was considered for Super Mario Bros. He explained in a recent edition of Iwata Asks that, although he believed fruit would have been a fine choice, players might run away from the fruit as a result of confusion. I suppose this makes sense, as a coin is an object that gamers would be more interested in collecting.
“Thus, when we were thinking about something that anybody would look at and go ‘I definitely want that!’, we thought, ‘Yep, it’s gotta be money.'”