When I install a program with Discover I can do so without typing a password. Uninstalling it however does ask for the password.
I reported this as a bug on bugs.kde.org: https://bugs.kde.org/show_bug.cgi?id=395750
Answer: This is a PackageKit policy, if you think it should report to your distribution.
What is a Packagekit policy, where does it come from and why is it there?
Installing is writing on the system disk and requiers a password. Why not now?
Pacman, Yaourt, Octopi all ask for a password, all except Discover. Why?
Is it a feature, is it a bug, what is it?