No, singling out one sentence from my answer and attacking it is a strawman.

But ok, to correct myself: without DRM ebooks would never exists at this scale and people would never buy ebooks readers at this scale and read ebooks at this scale.

Ten years ago ebook reader was a niche, used only by geeks. Today, thanks to aggressive Amazon pricing and (DRM-ed) ebooks, it's a common item. And popularity of ebook readers (namely - Kindle) started some new things: I love SF, and last year I bought a lot $1.99 books from self-publishing authors who would probably never find a place to publish their books without widely available ebook readers (read: Kindle). So, to return to original question - what are such a burning "problems" that Stallman predicted?

Agree, that is a better argument. But I think devices such as the iPad would have been released regardless of whether it contained iBooks with DRM or not. Answering your question, I think that Stallman is partially right, but not always, but then who is?

And such sellers and their customers can leverage the well designed e-readers that exist because Kobu and Amazon have business models supported mostly by the sales of DRM'd books.