well at first it was no big deal and was just a personal opinion but now i hate her more just because people are trash talking me and automatically calling me a stuck up person just for hating her. i cant like her if the fandom towards her are complete jerks >.<
They do teach friendship lessons in Season 3. However, they don't send letters to Celestia . If you listen, they actually teach them through the dialogue. If you need an example, here- [link]