It's all Hugh Grant's fault actually.
Note: we english actors are much better at putting on american accents, like Hugh Lauire in House. And we're better actors anyway which is why we always play the bad guys.
English person watching telly: "What a dipstick, using a typical stereotypeism like that."
American watching same TV: "Yeah man he got that Brit accent right on! GO AMERICA! WHO WANTS BEER AND CHIPS? HELL YEAH!"
*fight propmtley ensues*