ahi, 100 years ago most cars looked like horse carriages without horses. Simply because the first manufacturers of cars used carriages as a carrier for their motor. But automobile manufacturers surely have developed and created bodyworks to suit the needs of a motorized device.
Books are a stacked collection of rectangular cellulosis layers in fixed measurements. PDF indeed accomodates to this fact.
But - with all due respect - could/would/might it occur to you that books are but
one way to display text and/or graphically enhanced text blocks? Books are a medium with a long tradition which resulted in some finely crafted examples (some of which I am proud to keep in my shelves). But also with a lot of limitations.
There is no need at all that any eBook format besides PDF should ever have to follow the requirements, regulations and traditions of bookmaking? Why? What for? They are not printed on paper. They are not bound. They are not - and please accept this as a major advantage of eBooks - not limited to any page layout or size.
Your position on eBooks is that of digital versions of books.
Mine is that they are a new medium with new requirements and new demands. Some which we'll have to find out in the decades to come, some of which will be steadily improved. PDF might be
a part in it, ePub too.
I would rather like to call them
eScrolls than eBooks, since the basic text layout (I'm concentrating on novels right now, not magazines) is that of one large file with a beginning and an end. And some chapter intermissions inbetween. Quite like a scroll, definitely not like a book.
If you ever read some of the comics of
Scott Mc Cloud, you may understand that even graphically based layouts do not at all have to rely on paper size restrictions but free themselves from that concept.
You stick to books, I stick to content. Deal?