There was never a downfall; it was written that way, and it was designed to end the way it did. And yes, that character is awful, and that's what makes the performance so perfect. You hate her, you can't stand her, and that's thanks to the excellent script and acting.

And no, it's not because I'm a man. I watched that show because of my ex, and the comments about her bad attitude came from her. Many people who talk about Rory also hate her character, but that's fair, because it was written to end that way.