What are the complains? Just that it looks like an old 90s program, and doesn't have the latest all-white minimalist design? Or are there actual UX programs?
It looks like an old 90s Windows program, and most Mac users were bothered by those even at the time. It fails to honor basic common MacOS navigation keyboard controls, making it jarring even if I tune out the over-the-top ugly visual interface.
Old 90s Windows programs are great. Downright relaxing after the "WTF is interactive and what's content?" mess of "modern" UI. Calibre's not that. Some poster upthread got it right by comparing Calibre to some of the uglier examples of Java UIs.
