The question: “In the original production of Pygmalion, Eliza and Higgins have a romantic relationship. Why was this relationship de-emphasized in the adaptation to My Fair Lady?”
It is generally agreed that PYGMALION is primarily a social commentary/satire on the artificial barriers between social classes.
Actually, Shaw wrote repeatedly that PYGMALION was not a love story, and that Eliza goes on to marry Freddie after the play is over.
In fact, because both actors and audience members wanted Higgins and Eliza to end up together, George Bernard Shaw wrote an afterword to his play that declared emphatically that they never marry.
He says that Eliza marries Freddie Eynsford-Hill.
Shaw wrote an elaborate summary of Eliza and Freddie’s married life.
The play, unlike the musical, ends with Eliza leaving Mrs. Higgins’ house as Higgins laughs.
Shaw allowed a happy ending to be used in the film version of PYGMALION, in which Higgins and Eliza clearly will live “happily ever after.”
When asked why he allowed this, he replied, “I did not. I cannot conceive a less happy ending to this story . . . than a love affair between the middle-aged, middle class professor, a confirmed old bachelor with a mother fixation, and a flower girl of eighteen.”
So much for happily ever after. . .