Th JPG analogy does hold water - for a perfect ebook reproduction of the text, use a TIFF or bitmap or similar.
However, often an ebook is a lossy reproduction - look at the reviews for Surface Detail on Amazon. The quality of the text is below that of the published books (there are sections missing, large gaps in the text, inappropriate hyphenation and missing chapter breaks), and the ebook is more expensive than the hardcover!
It seems like the publishers are acting against their own best interests in the matter of ebooks, just like the music publishers acted against their own interests with music downloads. I agree with posters who claim that the books will be published eventually at market price; our problem is that the market is very slow to stabilise and we must suffer from inefficiencies in the market while it stabilises. The publishers seem to be the major reason for the slowness of the market and that's why people have a gripe with them.