Hello Reiner, Initially I thought it was better to add is a Dependency by the following Policy text: "The Depends field should be used if the depended-on package is required for the depending package to provide a significant amount of functionality."
I assume that as zenmap is a graphical tool, people will mainly start it from a DE, using the desktop file, and in order for that to work users will need polkit. Previous version were working for you because you either already had the menu package installed (which was a non-declared depends/recommends, this was fixed along with the polkit transition #890728) or you started zenmap from the terminal as root. I didn't realize polkit was dependent of systemd, but I just would like to make sure with the rest of the team that we can put polkit in Recommends even if it breaks the desktop file for zenmap as root. Thanks for reporting -- Samuel Henrique <samueloph>