The Exorcist may have indeed been more terrifying in 1973, but I think peope enjoy watching the evolution of horror, as much as they enjoy watching the films themselves. And because of that, The Exorcist is still fascinating. I agree that it isn't the greatest movie or horror movie ever made, and I'm a bit baffled as to why Mark Kermode for instance, of all people, would say so, but it has stood the test of time in opinion and it is still perfectly capable, if nothing else, as a horror movie. I saw it on the big screen earlier this month, the cinema was absolutely packed and the reaction of the audience was still visceral and genuine.