In the Movie Mask, at a few points in the movie people go up to Rocky and tell him to take off the “mask” that he isn’t wearing.
This is proven to be due to the people being unknowing of his facial deformations when he mentions to them it's not a mask and that he actually looks like that. The TV show Arrow has a lot of examples of crassness. Oliver Queen seems like just an extravagant millionaire playboy. People call him out as being arrogant, cocky, and uncaring. Little do they know he is working as hard as he can as the vigilante “The Arrow” to save the city that treats him poorly. They are uneducated on the fact that he is not who they think he is and that he is trying to save them more than they’ll ever
know. Overall, being crass doesn’t automatically lead to being stupid or being hateful it means to be uneducated and unknowing of the truth. This is shown a lot in literature, and film.