Does digital publishing encourage writers to write faster and with less precision? I think the answer has to be yes in the vast number of cases. It's like the pulp magazines in the first half of the 20th century. Stories were churned out. Magazines needed to be filled, writers needed to be paid, readers wanted something/anything to read.
Now we have a somewhat similar situation where so many ebooks are at a bargain price--you couldn't buy a magazine for what many digital books sell for--there's great enthusiasm to put books up for sale that might have benefited with a little more time in the oven. I suspect this will sort itself out. Readers are anxious to get books for $1, or $2.99 tops, so maybe they don't see the seams and the unpolished prose. Maybe no one cares anymore. Or maybe some do and are desperate to read something that's not about vampires. (Some explain the vampire thing to me, please.)
I still believe ebooks are here to stay, will only increase in sales and will sooner rather than later change the way traditional publishing operates now.