Citizen Kane - the greatest of the great?

The reason Citizen Kane is considered the greatest movie ever made might be because of its incredible techinal achievements. Indeed, its use of deep focus, "prismatic" non-linear narrative structure, as well as the novelty of camera angles all contribute to the movie's "greatness". However, should a film without a central plot or an antagonist still receive so much praise? Perhaps, back in the 1940s, the level of professionality with which Citizen Kane was created, overcasted the lack of story and the audience's emphathy for the character. Nowadays, most movie-goers are spoiled by everything from The Godfather to Starwars, where compelling stories are combined with mindblowing special effects and thought-through angles. It is not so easy to impress one with a humble film from the 40s that cannot be easily understood by an average person. The reason it is "the greatest movie", however, is because it is rated as such by critics who have the seen the way this film changed world cinematography at the time. For those of us who aren't film buffs this fact would be rather unknown and therefore, underappreciated.