One source of this is a trend that's existed for years, but because of the Kindle and other online electronic book marketplaces, can enter the mainstream. That is, "Private Label Rights" books have been available for years. The idea is that someone puts together a "book" and then licenses that book to others to manipulate, relabel, and present to the public as their own work. The result is someone presenting themselves as an author, but instead they're buying and algorithmically restructuring someone elses work. Algorithmically restructured text isn't as readable as text written by a human who cares about their work. Also it's not an original work despite being foisted upon the public as if it were.
As someone who is intent on writing short low cost but high quality books for these marketplaces I'm concerned that the market might be filled with junk. I don't want to produce books which will be shunned because they're sitting next to junk.
On the other hand Amazon, Barnes and Noble and the other companies running electronic book markets obviously have an incentive for we their customers to continue buying books and stuff .. hence, there is likely to be some effort made to screen out the junk. It's similar to the work by search engines to detect spamblogs and keep them out of search results.
I think there's potentially a lot of value to short low cost high quality electronic books. The markets allow a writer to more rapidly write and publish, especially if they're willing to do their own marketing.