Here's what King had to say about it.
"I'd admired Kubrick for a long time and had great expectations for the project, but I was deeply disappointed in the end result. Parts of the film are chilling, charged with a relentlessly claustrophobic terror, but others fall flat."
"Kubrick just couldn't grasp the sheer inhuman evil of the Overlook Hotel. So he looked, instead, for evil in the character and made the film into domestic tragedy with only vaguely supernatural overtones. That was the basic flaw: because he couldn't believe, he couldn't make the film believable to others.
The second problem was in characterization and casting. Jack Nicholson, though a fine actor, was all wrong for the part. His last big role had been in One Flew Over the Cuckoo's Nest, and between that and his manic grin, the audience automatically identified him as a loony from the first scene. But the book is about Jack Torrance's gradual descent into madness through the malign influence of the Overlook, which is like a huge storage battery charged with an evil powerful enough to corrupt all those who come in contact with it. If the guy is nuts to begin with, then the entire tragedy of his downfall is wasted. For that reason, the film has no centre and no heart, despite its brilliantly unnerving camera angles and dazzling use of the Steadicam. What's basically wrong with Kubrick's version of The Shining is that it's a film by a man who thinks too much and feels too little; and that's why, for all its virtuso effects, it never gets you by the throat and hangs on the way real horror should."