It isn't simply the narrow-minded hatred of people having a better time than she is that drives Elly's arch hatred of the ambitious. I sort of hinted at the REAL reason in my wrap-up, but now I'd like to expand, if I may. It's because they're getting ahead in the world without HER approval! The smug git is programmed with the inane drive to be the corpse at every wedding and the bride at every funeral, so she reacts to the notion that people doing things that don't involve her in a central role (if not the centre) with unalloyed rage. How dare these awful people not ask HER opinion? What are they thinking? That she's just some jerk housewife who isn't REALLY affected or involved and whose beliefs aren't germane? That she should just shut up and let other people get on with their lives? Sadly, Elly is a member of a vast army of people who long to have power over others without having the moral authority or wisdom to have her opinion really matter. She's thus doomed to a life of pointless frustration wherein the only thing people are left to wonder about is the number of innocents she'll take with her when she finally snaps.