it's also very "accessible" - good for assistive technologies and people with "ou-of-the-ordinary" requirements
Well, the problem is that you lose then all the semantic information that was encoded into the HTML or ePub versions. Those tend to be better for assistive tech users.
Not really, given that it can’t represent even basic formatting such as bold or italic text, chapter markers etc.
As an output format it’s ok, but as an input format, it’s almost as bad as PDF.