If you’ve seen pretty much any movie ever, you may have noticed the film industry’s weird tendency to drop British-accented bad guys into settings where, mysteriously, no one else seems to be British.
Elizabeth Hurley was the only one with a British accent in that movie Bedazzled, and she played the literal devil.
In one study, for example, a researcher delivered the exact same lecture in two different accents, receiving more positive reviews when he did it in received pronunciation.
On the other hand, though, RP speakers are also generally considered “less trustworthy, kind, sincere, and friendly than speakers of non-RP accents.”
And when you put the two together, you get someone with a fierce intellect and low morals — the perfect combo for a fictional bad guy.
Believing in this concept legitimizes the institutional discrimination of those who don’t use or didn’t grow up with the standard language.
But plenty of people in the U.S. think of the American accent as no accent at all.