Wow, I thought you were a twit before but now you have removed all doubt. No one with half a brain considers any of the three you listed as on the same level as Hemingway. Melville is several levels above Twain or Steinbeck - I have never met you and I'm embarrassed for you that you are so oblivious to your fathomless ignorance as to type a sentence that values those two above Hemingway - but, good as he is, he didn't change all of literature as did Hemingway.
You can find plenty of third-rate hacks who teach Comp 101 at community colleges who will disparage Hemingway for the price of a latte at Starbucks, and it's a sure sign of a tyro who has no understanding whatsoever of literature or art. You'll never find an important critic who puts any of the writers you listed above Hemingway. No writer since Shakespeare has influenced literature as much as he did. I could teach you but it would take months, or in your case more likely years, and you would be too busy mocking to learn anything.
Every two-bit producer in Hollywood knows what subtext is, and faults any script that doesn't have it in the dialogue. There was no subtext before Hemingway: every writer, Shakespeare included, told the reader what he was supposed to feel at any given moment. Hemingway so thoroughly changed literature, and by extension art, that it's impossible to fully grasp his influence because it's everywhere.