Well, the Zap Apple episode did give Silver Spoon some redeeming qualities. She was the first one to start applauding Granny Smith after her story. They could easily play it off as her just acting like a bitch to have Diamond Tiara as a friend.

And Filthy Rich was shown as a pretty good dude, even punishing his daughter and showing a great amount of respect to the Apples. So I doubt her problem has to do with any upbringing.

That's rich, coming from Worst Pony.