I loathe the book management parts of calibre too. I only use the command line tools.
A fork with a sane GUI would kill calibre.
A fork with a sane GUI would kill calibre.
I stopped using it because I can't stand the UI :(
Edit: if someone were to publish independent mockups for a new Calibre UX, it could motivate community feedback and/or dev contributions. The ebook market is larger now than a few years ago, given the rise of mobile.