Traditionally carrots were used as the main sweetener in carrot cake. Something developed during lean times when honey, fruits and sugar weren’t available. So assuming this person was looking for a “low sugar cake” recipe, they may have found a carrot cake recipe that only used carrots for sweetening.

… and then they removed the carrots to reduce the sugar content further. So yah it’s going to be an awful cake if there is zero sweetness in it. Like, just make a savory baked good at that point.