I've never fully understood people's obsession with George Bernard Shaw. He's a decent enough writer, but it seems to me that his abilities with dialgoue are somewhat overpraised. Not to say that he's bad at writing dialogue or anything, but to compare him to, say, P.G. Wodehouse, or Oscar Wilde, or Douglas Adams, or Mark Twain... it just seems wrong. He just strikes me as a second tier author, who's been misplaced on the first tier by people who like My Fair Lady more than they should. He can write good dialogue, but it rarely soars. Yes, you do get the occassional gem, like, "I shall make a duchess of this draggletailed guttersnipe," but most of the time it's just... solid. Each of his characters do have a different and unique voice, but most of the time those different and unique voices aren't really all that interesting.
Don't get me wrong. I'm not saying that I dislike Pygmalion, either the original play, or the 1938 film version directed by Anthony Asquith and Leslie Howard. I just don't think it's some amazing work of genius. It's a solid piece of romantic fluff, that was thought to be something more by some of its makers. Yes, it works as a criticism of the social class system in England - it points out the injustice of people being placed in different social spheres based on their accents and grammar. Except that the film (or the play) never go so far as to say that people shouldn't be judged based on their accents, just that the poor should be taught to speak properly. So the play (and the film) basically hold the exact same prejudices that they are trying to criticise.