I felt that she got what she deserved !
when Big did not show up in the wedding, Carrie must have felt exactly what she had made Aidan feel a few years ago, time and again !
First she cheated on him. Then she refused to marry him, because... she was not ready for marriage, yet she was more than ready to marry Big - before Aidan - and even asked "why not me" when Big married the Ralph Loren model.
So why Big was ....bad Doing exactly the same thing that Carrie did being...smart and cute....and crazy girl ???
Carrie is the one that enjoys being humiliated ! She liked punishment ! When treated with respect and love, the only thing she gave back was betrayal !!!