The manipulative narrator, is it okay to deliberately mislead readers?

One school of thought has it that book narrators are honor-bound to reveal all they know as they know it over the course of a book. This “rule” applies in particular to first-person narrators who can only avoid it by deliberately misleading the reader. The key word here is deliberate. It is what prevents these narrators from being merely unreliable. We call them manipulative narrators.
A famous example is WHO KILLED ROGER ACKROYD by Agatha Christie. The book is narrated by Dr. James Sheppard, who attaches himself to Detective Hercule Poirot to help solve the murders of Ackroyd and his fiancé, Mrs. Ferrars. As the local doctor, Sheppard comes across as a sympathetic character with a penchant for village gossip:
“Wasn’t it sad about poor dear Mrs. Ferrars. A lot of people had been saying she had been a confirmed drug taker for years. So wicked the way people went about saying things. And yet, the worst of it was there was usually a grain of truth in these wild statements. No smoke without fire!”
The twist is that Sheppard is the murderer, something that is revealed in an epilogue after Poirot eliminates all the other suspects. Yet, the reader has been going along thinking that Sheppard is telling the truth and can be relied on. But the one salient point that he did it undermines everything. When the book was published in 1926, its manipulative narrator caused a great deal of discussion and controversy.
By contrast, Ian McEwan’s ATONEMENT inspired little similar discussion when it came out in 2001. Yet, in this book the identity of the manipulative first-person narrator is hidden until the end, the reader thinking that multiple other voices are telling the story, including a third person one.
The Scotsman of July 22, 1926 states the case:
“When in the last dozen pages of Miss Christie’s detective novel, the answer comes to the question, “Who killed Roger Ackroyd?” the reader will feel that he has been fairly, or unfairly, sold up.
Fair or unfair, what do you think?