Because it's not a book-reader, but a suit of tools for ebooks. Which includes managing them, receiving data from certain source, reading them, converting beetw

Because it's not a book-reader, but a suit of tools for ebooks. Which includes managing them, receiving data from certain source, reading them, converting beetween different formats, automating certain managment-tasks, offering a web-interface as also desktop-interface, and finally also managing synchronisation with many many ebook-readers (for which the mounting is neccessary). And it BTW has a very elaborated plugin-system which allows to add even more that what it can do out of the box. It's more justified to call it an IDE for Ebooks.