He wasn't the first director that wanted to do something and was told it couldn't be done; he was just the first one that did not accept that as an answer.

Because of that, he allowed a great many better filmmakers to explore a new realm of visually believable story. Because of his business acumen, he changed the way films were marketed and profited from. He deserves his placement in cinema history, not for what he did, but for what he demanded that others provide to him. His place in cinema history is that of being the arrogant asshole who demanded that his people do what everyone knew could not be done. Fortunately, they could actually do it. Thus, a mediocre remake of The Seven Samurai became one of the most iconic and pivotal movies in history.

He deserves the acclaim for what he is, and what he accomplished, but he is not influential (as I define the word). He did not influence, he simply showed that the previously assumed limits did not apply... "If that hack George can do THAT, just wait till they see what I can do!"