SUMMARY On windows you can use shortcut Strg + F4 to close apps and if all apps are closed or the focus is on the desktop, the shutdown dialog was shown. Strg + F4 is a very common shortcut to close apps which work not only on Windows, it also work on Plasma, Gnome, ... I suggest to show the shutdown dialog when the focus in on the plasma desktop (or all apps are closed, which mean the focus is on the desktop) cause you don't have to navigate through the start menu to shutdown the computer.
What's wrong with Ctrl+Alt+Del? That will show the shutdown dialog and automatically quit all apps before shutting down when you choose one of the options?
Ah > 10 years ago Ctrl+Alt+Del was a common shortcut and I use it a lot. Now I forget it. I suggested Ctrl + F4 cause it's the same close shortcut as for apps. But I'm fine with close the bug report.
Do you think of alt+f4 and not ctl+f4?
*** Bug 422631 has been marked as a duplicate of this bug. ***