Probably because some writers probably don't know her character outside of the cartoon, so they write her as as the sarcastic snarky goth they're familiar with. (Don't get me wrong, I like Toon!Raven. I just like my Toon!Raven and Comics!Raven as separate characters)
Then again, the main man, Marv Wolfman wrote Raven saying this in response to Supergirl saying, "Aren't you supposed to be a pacifist or something?" She says, "Old body. New body, not so much." Brave & The Bold #17 an #18.