You're drunk. I haven't watched the new ep yet, but her other episodes have made it clear she is quite generous. You're all silly for thinking having standards is being a bitch. You're relying on stereotypes set by other shows; she's overdramatic, sometimes, yes, but she goes out of her way to share her excellence with others.
That's what generosity is: charity. People would probably call Bill Gates a bitch if he was a girl, but he's the one donating billions of dollars to people in need. He still has high living standards for himself, but he's generous. Don't mix it up with kindness, that's fluttershy's thing and she can't hold her own whereas Rarity doesn't need anypony to hold her own, she's a strong individual and she enjoys sharing the reaps of her efforts with others to better their lives.