I cannot understand why the film makers of Pygmalion (1938) and My Fair Lady (1964) have Eliza (Wendy Hiller/Audrey Hepburn) return to Higgins (Leslie Howard/Rex Harrison) in the end. It is by no means a happy ending. All the trouble of her transformation results in her just to be a slipper fetcher--how depressing. I can envision their future life together: Eliza taking care of Higgins' appointments and making life easier for him; but, when she receives no attention or kindness for it, she resents herself and Higgins, and erupts in violent episodes of mania and self-hatred.
I will attempt to find the screenplay writers' possible motive for ending the movies as they did. I will also explain why Gabriel Pascal, the producer of the 1938 film, directed by Anthony Asquith and Leslie Howard, persuaded Shaw to go along with the new ending. Shaw's ending was not inane and would have made for a rather pleasant completion to the story in both versions, the second of which was directed by George Cukor and based on the 1956 musical by Alan J. Lerner and Frederick Loewe.
On Eliza's return, perhaps the writers were insinuating that Higgins would have a change of heart and fall in love with Eliza. This is implausible and contradictory to Shaw's intent. The character of Higgins is ruled by the head, not the heart. He sees no logic in love and all its affections. He compares the love between man and woman to commercialism or trade in affection. How could a man so distanced from sentimental impulses ever change his ways? Of course, he could not. Higgins is truly a confirmed bachelor; and the story is all the more intriguing for it.
Maybe the writers expected that Eliza would be content with Higgins' indifference, and they would continue living together "for the fun of it," as Higgins suggested. This is almost as unlikely as Higgins' falling in love. A woman, by nature, desires to be desired and needed. I do not think I have ever met a girl who would consciously choose to live with a man who is apathetic to her presence. However, one could argue that Eliza is the exception since she has received this kind of treatment all her life. This is an idea I might believe because Higgins is very similar to Mr. Doolittle in that neither is particularly kind to Eliza, or anyone else for that matter; and from a psychological standpoint we are most comfortable with what we are most familiar with. Yet one must take into account that Eliza did not sit idly by and take her father's treatment (or non treatment). She was out on her own at a very young age supporting herself. This, however, would not harden her so much that she would not desire affection. This is obvious from the dissatisfaction she displays regarding Higgins treatment of her. When Eliza tells Mrs. Higgins that she learned to become a lady when Colonel Pickering called her "miss," her treatment preference is established. Later, Eliza blatantly declares to Higgins that all she wants is a little kindness. Therefore, it would be impossible that she would choose to return to Higgins, only to receive the same treatment.
Why did not the film makers leave the ending as Shaw did? They could have incorporated Shaw's epilogue with scenes of Freddy and Eliza in their flowershop or taking a holiday in the country. They even could have showed Eliza visiting at Wimpole Street; bickering with Henry like a sibling. That ending would have warmed my heart. Granted that Freddy is not dashing and debonair or even competent, but he and Eliza fit together like an intricate psychological puzzle. Eliza has been self-sufficient most of her life. She would be most happy if she continued to be so. The only thing she is missing is affection. Who is better for her than an incompetent devoted fool aching to spend every waking moment at her disposal? It is the happiest and most sensible ending. If Hollywood, or the British equivalent, had not the immediate impulse to couple hero with heroine for the sole purpose of gratifying these inane romantic illusions, they would have had Eliza marry Freddy.