I find the Torrances some of the most sympathetic characters Stephen King ever penned. Jack Torrance simply wants to redeem himself (man up) while on the verge of hard times but discovers evil lying in wait for him and the family up in the snowbound Rockies. In the movie, we dont ever truly get a glimpse of the redeemable qualities of Jack Torrance before the madness. Jack Nicholson is simply too creepy right off the bat. In the movie, everyone just does their own thing. Danny is constantly alone on his big wheel talking to his finger friend Tony whereas in the book Danny actually goes under in a trance when Tony contacts him there's a gulf between them and Tony appears to speak across this distance like a teenaged Guardian Angel. In the book, the Torrances are an attractive couple just attempting to bury their pasts and plow full steam ahead to rebuild their once prestigious lives. Jack Torrance really has something to prove here. Jack was an ex school ballplayer. Wendy is not this meek and insecure mouse of a woman like Shelley Duvall in the movie. Kubrick changed too many dynamics and by this really failed to flesh out these characters.
I agree, a movie from a novel rarely cuts it, imo. I never read the book.