Economy of words makes your message stronger. Using too many that are extraneous distract and dilute it. This is why adverbs, adjectives, and prepositional phrases often add extra bulk that should be trimmed. Being too wordy indicates lack of skill and trouble expressing what you want to say. When you’re talking aloud you can get away with fumbling around a bit, but not in print.
On the other hand, people who talk too much are usually annoying. Thus, by extension, it can be pretty grating when an author takes too long to say something. Readers are not the most patient people out there. Everyone these days is pretty busy and doesn’t want to waste their time with someone beating around the bush.
If you can say the same thing with less words, do so. Start by zapping adverbs by using a better verb, then see if those prepositional phrases really add anything to the story other than word count. Some writers have a tendency to add a prepositional phrase on the end of a sentence that is totally redundant. Make sure you’re not one of them.
Back when the dinosaurs roamed the earth and I was in high school, my Senior Lit teacher instructed us to avoid using the same word more than once in a paragraph, much less sentence. Unnecessary words slow down your story and thus frustrate or even annoy the reader. If you need to repeat the word for clarity, try a synonym. In many cases, this is a job for pronouns. If all else fails, rewording the sentence or combining it with another one will do the trick.
Using the same word repeatedly shows lack of writing skill and/or laziness to refine your own work. I recently read a novel that comprised a clever, interesting, and suspenseful story, but the author clearly didn’t understand this concept. There was one paragraph where he used the word “hangar” (in reference to those buildings where you park airplanes) five times in one paragraph. It was even more amusing since he spelled it “hanger” a couple times instead. Am I the only reader who catches such things? I can’t help it, but I edit as I read something that is poorly written. To this book’s credit, there were very few typos, only two or three, where it was something a spellchecker would miss but an alert reader or editor would not, since it was clearly the wrong word.
Like I said, the story was good, the writing and editing sub-par. This happens a lot with indie novels. I suspect this particular story would have been 10% shorter if cleaned up properly, saving the reader not only time but the energy expended in rolling his or her eyes.