I think I may know of a way that Hasbro could appease both the Brony community and the soccer moms after this whole Derpy controversy: Have an episode focusing on Derpy and one(or all) of the Mane Six.
Now here's what I was thinking for an episode idea: Rainbow Dash would end up having to work with Derpy. Dash takes Derpy under her wing(no pun intended) and they do things like changing the weather and such but as they continue working together, Dash finds that Derpy keeps messing things up. After awhile, Dash's patience has grown thin and she yells at Derpy about how she's had enough with her constantly screwing things up. Of course this makes Derpy really upset and she flies off. Realizing just how badly she hurt Derpy, Dash tries to find her and apologize. She eventually finds Derpy, sitting by herself, crying and talking about how she can't do anything right. Dash realizes that despite how things look, Derpy really has been trying her best. She approaches Derpy and apologizes, explaining that what she said was out of line and that she'd be honored to receive Derpy's help. The two of them make up and the episode ends with Dash helping Derpy to clear the clouds. The letter to Celestia would be about how some ponies need a little more help than others and that you need to take your time with them. And even though that pony may mess up sometimes, that doesn't mean that she's not giving it her all. The End.
So what do you guys think? Comments, suggestions, etc. are welcome.
