The original short story was, indeed, to inform women that not all medical care of the era was helpful. The story was formed out of her (Gilman's) own personal experiences. In Gilman's original work, John is eccentric, yes; He is a stickler for structure. But he is not as cruel in the story as he is portrayed in the film. The scene where he takes her upstairs and forces himself upon her in the film? In the book, he carries her upstairs and sings her to sleep. Yes, the film does have vague feminist tones, but not nearly to the degree of the film. The sick twisting of John into an arrogant, careless doctor from a confused husband who tries his best to help is very unprofessional.
John sincerely wishes to help his wife in Gilman's original storyline; he does everything in his power to do so, using the best medical techniques of his time. The focus is on the fault in the techniques of medicine, not the fault of the man.