Thus, we have to give an edge, a slight edge, to published authors over Indie or self-published authors. That's why I'm proud to say that my first novel, Rebels on the Mountain, was published by Gallivant Press, an imprint of Venture Galleries. Gallivant is the enterprise of two men, Caleb Pirtle and Stephen Woodfin, respected authors themselves. I was honored to be among the first writers that they chose to publish.
Should Amazon provide separate categories for published and Indie-authored books? Well, readers can at least depend upon the fact that published books passed some kind of test. They're at least good enough for someone other than the author to invest in publication and promotion. But, until publishers begin hiring editors again to clean up manuscripts and challenge authors to make them better, that's a scant advantage.
Although you can find two collections of my blog postings on Smashwords, Infantry School and Vietnam – A Soldier's Journals, I'm still not an Indie author. My first novel, Rebels on the Mountain, as well as two earlier books were published. The earlier books were traditionally published. Not only were they printed, but also they were edited because they were published in a time when the book market was thriving and the economy hadn't sunk so low. (You may choose your favorite scapegoat to kick down the road for this problem.)
Ultimately, I wish that my publisher would display their badge on the cover to let readers know they found my story compelling. That might just help me as well as other newly published authors become discovered. Also, you can bet that our publishers wouldn't mind seeing a healthier return on their investments. However, most importantly, it might just help readers make better choices from the myriad of books that are being published every day.