Celestia in the past was portrayed as a selfish, idiotic jerk because she KNOWINGLY put two entire universes at risk so she can get the D from Alternate Sombra. Also it flat out said that she in a way replaced Luna who was trapped in the moon, and also that Celestia and Starswirl just shrugged off Luna's depression, anger, and other signs of becoming Nightmare Moon in favor of traveling to other universes. This made Celestia look very uncaring for other ponies aside from Sombra.

Starswirl is just a flanderized Pinkie Pie if she was instead an old man. Really, though, Katie Cook seems to think that characters are "improved" if they just become random and lulzy (look what she did to Starswirl, Luna, Shining Armor, Chrysalis, and the Cutie Mark Crusaders). It brought nothing interesting to his character and they could've done so much since we know so little about him, but no, random and lulzy, wash rinse repeat.

You can take them or leave them as you please.