> (Authors and publishers need any bit of good news they can get right now.)

Amazon accumulating even more control over the ebook market is not good news for authors and publishers.

I agree that Amazon getting even more control over the ebook market would be bad for authors and publishers.

But how would (hypothetical) more formidable DRM constitute even more control over the ebook market?

(Do you mean more control by preventing more piracy? Or by preventing more good-faith circumvention? Or more control because ebooks might be published even more Amazon exclusive than they already are, because of superior anti-piracy protection?)