Originally Posted by tompe
Isn't this discussion about books that do not work on the Kindle as a default? And then I would say that the copyright holder have in many cases explicitly not made the book available on the Kindle.
Publishers can't have it both ways, if they control access via DRM then the DRM defines which devices are allowed access. The copyright holder accepted the Kindle PID and (via their agent) stamped this PID as "authorized" inside the MOBI ebook. This PID is unambiguously for a Kindle, and the ebook in question (with DRM intact) does run on the Kindle. It isn't the copyright holder who is preventing this ebook from running on the Kindle, it is the Kindle's manufacturer (Amazon) who is doing so.
Kindle owners who read kindlefix-ed ebooks on their Kindle may be violating Amazon's terms of service, but this isn't an ebook copyright violation and there is nothing illegal in Igor's software.