There must be some misunderstanding

Note to self: next time you're being a pedant and mentally tut-tutting at someone's verbal faux pas, just consider that you could be witnessing linguistic evolution in action. Here's David Shariatmadari to explain why error is crucial as "the engine of language change" and to explore some "wonderful examples of alternative pronunciations or missteps that have become standard usage".

(Thanks to Joe for the link.)