Showing drastically increases word count and gives every writer a chance to show off.
Telling, except on rare occasion (when required) is the mark of an amateur because it represents an opportunity the author had to give a unique or genuine or entertaining spin on something mundane, but elected to pass instead (or just plain outright missed it, which is equally as bad).
(Personally, I think male authors are typically more guilty of this faux-pas)
Writing a book is fucking hard, man, especially when you're just starting out. Well, I should rephrase that to say that writing a good book is hard. Crappy books are inevitably filled with too much fluff, and any number of other flaws; terrible and/or unrealistic conversations/progressions/transitions, a demonstrable lack of understanding as to human characteristics, qualities, and typical responses, and often just a poor foundation to the entire book. One of the most challenging aspects of writing a book comes when you're shooting for an arbitrary word count. Your story may be 30,000 and perfect acceptable but the publisher/audience requires 60,000 words.
That's when the author's ability to stretch and draw out certain areas of the narrative is so important. You learn to do a shitty version of this in school that usually succeeds because the teacher doesn't actually really care about anything you've written and doesn't criticize it very harshly because of the inevitable outrage that follows if they do. A certain amount of fluff is inevitable and, indeed, required for a good story. It's the fat of the story. Some fat is good. Too much fat is not. The danger is that every time you start wandering away from the clear path of the main story, you risk losing or alienating your audience.
(see; the current state of affairs with Wheel of Time)
The real skill is to insert the fluff/fat in such an entertaining fashion and seamless manner that the audience doesn't realize that what they've just read is completely unimportant to anything related to the progression of the story. They don't care because it's good. That's where showing vs. telling becomes so important - showing the audience what a badass a character is, or why they're insanely attractive, or why they're so dangerous not only provides more interest, it makes the story that much longer!
"Todd was a badass, but none of us liked him."
Todd burst in through the front door as we were talking about him, startling more than a few people as the heavy door banged off the doorjam. His face was stuck in it's usual expression somewhere between a scowl that challenged every face that had just been talking about him, and a contemptuous sneer as every pair of eyes darted away from his own. He walked to the fridge and snatched out a beer, tearing off the cap (whatever this is called, I don't drink) with his bare hand without missing a beat.
Look at that wordcount different, goddamned it.
A good writer can make almost anything interesting. Anything. Provided they're allowed freedom, and the ability to wander about like a crazy person.
Anyways, that's it for today.