In creating Dr. Henry Jekyll, a relatively ethical character who feels such intense societal pressure to be perfect, Stevenson seems to comment on, indeed criticize, the society that would drive a man to such lengths in order to rid himself of what seems to be a natural part of human nature. Jekyll felt the need to "conceal his pleasures," as he writes in his final letter, and he felt a "morbid sense of shame" concerning them. He "stood already committed to a profound duplicity of life," and the need to hide any moral imperfection (as determined by his society) compelled him to try to eliminate those imperfections altogether.
However, he reasoned, and it seems that Stevenson would expect us to agree, that "man is not truly one, but truly two," and so Jekyll's attempt to rid himself of his socially unacceptable desires amounts to the attempt to eliminate a fundamental part of himself as a human being. Further, his inability to control this side of himself, once he has unleashed it, indicates that his experiment should not have been attempted, that, in trying to eliminate his immorality utterly, he actually allowed it to become stronger. Therefore, society's attempt to regulate morality to such a great degree, such that a well-respected doctor fears for his reputation over a few minor desires, must be considered not only unrealistic but also dangerous. The more people feel repressed, the more urgent the desire to break through the boundaries imposed.