I have always been "aware" of the concept that they can be perceived as arrogant, but really only "colour" - it sounds kind of deliberate and like some attempt to sound "fancy," like enunciating "theater" as "thee-AY-tour" But even so, I usually see it as a humorous thing. The person is purposely trying to sound over the top arrogant/refined as a joke. I've never actually read "british" spellings and gone "what an ass." I usually assume that's how they write or it's a joke.