Princess Celestia isn't as kind as you think she is. If you look at it from a historical view she is literally following the rules of Machiavelli the Prince almost down to a tea. She removed Luna when she was corrupted by nightmare moon because she was a threat to not only her power but also the state. By making her an example she put fear into her subjects that if they did something wrong she would banish them as well. I could go into deep reasons and other but that would be a massive headache and I think the nightmare moon is the best example for the moment.

Well, NMM liked night, in moon is night 24/7 It's more a ironic punishment. Like turning Discord to stone (a quite molecular level stable substance) or vanquishing Chrysy with a mushroom cloud of love...

Disappointed when I saw that we would be discussing ponies, not the presidential candidates.

There's always next time!

Appliance, I am terrified to mention real world politics on the internet! Thar be windigos in those waters.