Starting with 2001, his movies became very cold and distant.

Kubrick's earlier films, such as Paths of Glory, Spartacus, Lolita and Dr. Strangelove have a much warmer, human feeling than everything he did after 2001. He seems to have adopted a very cold, distant and impersonal style for his futuristic film and just hung onto it for the rest of his career, regardless of the genre he was working in. Even his other historical epic besides Spartacus, Barry Lyndon, has this inhuman coldness and impersonality to it.

It's very difficult to look at his later films and accept that the same man who made Spartacus and Paths of Glory also made 2001, Barry Lyndon, The Shining and Full Metal Jacket.