Whonix is described as 'Desktop operating system designed for advanced security and privacy. Whonix mitigates the threat of common attack vectors while maintaining usability. Online anonymity is realized via fail-safe, automatic, and desktop-wide use of the Tor network' and is a popular Linux Distro in the os & utilities category. There are more than 25 alternatives to Whonix for a variety of platforms, including Linux, Debian, GNOME, Windows and Web-based apps. The best Whonix alternative is Linux Mint, which is both free and Open Source. Other great apps like Whonix are Debian, Tails, elementary OS and Kubuntu.
Mint isn't privacy focused at all. Not a bad distro, just not an alternative to Whonix.