Suffice it to say that breadth of vocabulary is a poor rubric for evaluating literary works, almost without exception. For Hemingway and many others, it is better to have the words at hand than forcibly to use them. For a reader, it is worth reflecting on why a writer chose the words they did, rather than assuming they could have done no differently. Much of the history of high-brow English literature consists of taking old forms and making them more nearly vulgar. More than a century before Hemingway, Wordsworth made a name for himself for his vernacular—to pick an example out of a hat. Closer to Hemingway's time, Mark Twain famously cut down James Fenimore Cooper for failing to "[e]schew surplusage" or "[e]mploy a simple and straightforward style"[1], adages that Hemingway can be said to have written by, at least in his best-remembered works. Hemingway fulfilled—or continued to work toward—one of the stronger and more common impetuses in English literature and criticism: to write using ordinary language, and to do so exactly.

I would add that it is useful in the study of literature and literary criticism to dislike something, particularly if it is an entrenched part of whatever canon you find yourself surrounded by. It means you have something to think about, concerning the work, yourself, and others. Which are the three most important things with regard to art—not in any particular order.

[1] http://twain.lib.virginia.edu/projects/rissetto/offense.html

On being informed that Faulkner had said that Hemingway "had never been known to use a word that might send the reader to the dictionary.":

"Poor Faulkner. Does he really think big emotions come from big words? He thinks I don't know the ten-dollar words. I know them all right. But there are older and simpler and better words, and those are the ones I use."

Interestingly, he says an expanded variation of the same thing in the OP:

“The test of a book is how much good stuff you can throw away,” he said. “When I’m writing it, I’m just as proud as a goddam lion. I use the oldest words in the English language. People think I’m an ignorant bastard who doesn’t know the ten-dollar words. I know the ten-dollar words. There are older and better words which if you arrange them in the proper combination you make it stick. Remember, anybody who pulls his erudition or education on you hasn’t any.

  His briefcase was lying open on a chair near the desk, and the manuscript pages
  were protruding from it; someone seemed to have stuffed them into the
  briefcase without much care. Hemingway told me that he had been cutting the
  manuscript. “The test of a book is how much good stuff you can throw away,”
  he said.
  
  “When I’m writing it, I’m just as proud as a goddam lion. I use the oldest words
  in the English language. People think I’m an ignorant bastard who doesn’t
  know the ten-dollar words. I know the ten-dollar words. There are older
  and better words which if you arrange them in the proper combination you make
  it stick. Remember, anybody who pulls his erudition or education on you hasn’t any.
  
  Also, daughter, remember that I never carried Teddy bears to bed with me
  since I was four. Now, with seventy-eight-year-old grandmothers taking
  advantage of loopholes in the G.I. Bill of Rights whereby a gold-star mother can 
  receive her son’s education, I thought of establishing a scholarship and sending
  myself to Harvard, because my Aunt Arabelle has always felt very bad that
  I am the only Hemingway boy that never went to college. But I have been so
  busy I have not got around to it. I only went to high school and a couple
  of military cram courses, and never took French.
  
  I began to learn to read French by reading the A.P. story in the French paper
  after reading the American A.P. story, and finally learned to read it by
  reading accounts of things I had seen—les événements sportifs—and from
  that and les crimes it was only a jump to Dr. de Maupassant, who wrote
  about things I had seen or could understand. Dumas, Daudet, Stendhal, who
  when I read him I knew that was the way I wanted to be able to write. Mr. Flaubert,
  who always threw them perfectly straight, hard, high, and inside. Then Mr. Baudelaire,
  that I learned my knuckle ball from, and Mr. Rimbaud, who never threw a fast ball
  in his life. Mr. Gide and Mr. Valéry I couldn’t learn from. I think Mr. Valéry
  was too smart for me. Like Jack Britton and Benny Leonard.”

That said, I can understand someone objecting strongly enough to his themes to not enjoy his novels as literature. (The same could be said of Fitzgerald in the same general timeframe.)

But I have trouble seeing how any of that translates into an argument for poor writing unless the lack of overly ornamental writing be considered a flaw.

I was amazed because it seemed to me that very little happened in the story. The plot, characters and character interactions are very simple. Yet, I couldn't put it down because it was so compellingly written. It was superficially simple, but incredibly deep because of what it deliberately left out. I'd never read anything like it.

I wish I could get across to you what you are missing because appreciating Hemingway introduced me to a different way of enjoying literature.

He is himself, also, as real life characters go, one of the greatest and most interesting I've ever had the chance to read about. What an eccentric and alcoholic lifestyle.

I could see not liking being forced to read his work though. Like the author of As I Lay Dieing which was itself a tough read, I really needed the time and mood to truly enjoy it.

I haven't read much in years, but some time ago, I opened A Farewell to Arms, and I must say that the first few pages are beautifully written.

The notion of conveying a powerful message or story as simply as possible is not an easy task, albeit seeming so.