I would say that Ishiguro has achieved the task he set out for himself through the construction of Stevens in The Remains of the Day.
One of Stevens's primary purposes is to establish the idea that people have to come to terms with their past identities. Ishiguro explored this idea through the character of Ono in An Artist of the Floating World. Just as Ono struggles with his past and must come to terms with it, Stevens must do the same.
The journey through the English countryside provides Stevens with the opportunity to evaluate the choices he has made in his life. In many instances, he must acknowledge that his embrace of the professional life in such a singular manner had blinded him to other considerations:
How can one possibly be held to blame in any sense because, say, the passage of time has shown that Lord Darlington’s efforts were misguided, even foolish? Throughout the years I served him, it was he and he alone who weighed up evidence and judged it best to proceed in the way he did, while I simply confined myself, quite properly, to affairs within my own professional realm.
Whether it was his failure to speak out regarding the dismissal of the Jewish maids, his inability to act upon his emotions in his personal life, or his flawed glorification of Lord Darlington, Stevens must undergo intense self- examination. At moments, he experiences the pain that comes with wisdom, and the hurt that accompanies insight.
Ishiguro is direct in his purpose. Self- reflection is a necessary part of human existence. Through Stevens, Ishiguro is insisting that individuals cannot "simply confine" themselves to "affairs" that lie solely in our "professional" condition. Like Stevens, we must gain understanding that there is more to our being in the world. As Stevens acquires such insight, it becomes clear that Ishiguro has achieved the task he set out for himself.