This question originally appeared on Quora. 
Answer by Ken Miyamoto, Produced screenwriter, former Sony Pictures script reader/story analyst, former Sony Studios liaison
Martin Scorsese is an American icon. If there ever were a quintessential American director that captured Americana so well throughout his whole career, it would be Martin Scorsese.
Mean Streets. Taxi Driver. Raging Bull. The King of Comedy. The Color of Money. Goodfellas. Casino. Gangs of New York. The Aviator. The Departed. Hugo. And now, The Wolf of Wall Street.
And best of all, his films transcend geographical boundaries. International audiences get to glimpse into Scorsese's interpretation of America, and beyond that, they are usually engaging and compelling stories with engaging and compelling characters.
The stories he tells are often tragedies, showcasing the underworld of society or the underbelly of high society, be they mobsters, Hollywood icons, brutes, or the rich and powerful. And there's nothing more engaging than seeing a character rise and fall. We become enticed by their success, living vicariously through them, and then are able to jump back into our moral judgement as we watch them fail. No different than how our society often regards the rich and famous, thus the compelling nature of these stories is embedded in our psyche and DNA.
Take The Wolf of Wall Street as a prime example. We become intoxicated by the success of these characters and then, when we've perhaps been shown that money isn't everything, we're allowed to step back and judge these characters as they fall. We feel bad for them because they've been humanized, but we quickly learn the error of their ways and thus, we appreciate where we are in our lives, without the fame, fortune, or thrills.
Scorsese is a great story teller. Plain and simple. He surrounds himself with talented casts. He's a true craftsman behind the camera. His cameras become a character themselves, whether they are tracking, uncut, through a room or multiple rooms or as they remain static, observing the emotions of a character.
He's not afraid to be provocative, brutal, and utterly violent. BUT, he doesn't make that his trademark. The violence is always an extension of the story and character, not a crutch, for shock value, or style (Perhaps the ultimate difference between him and Quentin Tarantino).
He is Martin Scorsese. A pioneer in contemporary cinema. He changed the way films were made and how cinematic stories were told. He was and always will be one of the "beards"... those cinematic pioneers that changed film.