I thought they already stopped more or less using their mascot because of the modern unpopularity of clowns, and the fact that they morphed from circus and birthday fools to horror icons.

As I said somewhere before, it's kind of shocking to realize that Krusty the Klown is the closest thing left to the traditional clown in modern pop culture, and he was intended to mock the traditional TV clown (particularly Bozo and his franchise.)