well.. you had celestia openly admitting about the throwing pie thing as bad as it can get. however there were both invasion, sombra enslavement in the past, applejack defeating and seemingly killing three timberwolves (With spike apparently killing the giant version.) hell Fluttershy admitted nature fascinating as she saw two predator (Chupacabra and vampire jackalope's) battling each other to the death to see who get to eat the mane six in the comics. i'm not saying he wrong but he far from right in suggesting that they live in a rose-color glasses world in the show.
It's meant to be Celestia being an idealist, but I think internally, the ponies don't get into major battles often.
fair enough