Uh ok 1st the issues regarding discord is celestia's and Luna's fault seeing as they sealed him last and just turned him into a garden ornament. 2nd starlight stole the time spell while celestia's guards were on shift, so her fault. Twilight went back in time and corrected it over a dozen times. 3rd lets look at every major catastrophic event and villian all past issues Celestia and Luna used a temp fix to deal with. Or never informed twilight or her friends about.