Fpmurphy has created a Gnome Shell extension that adds a power off option to the Gnome Shell user menu. This makes it so you will not need to press Alt, with Suspend selected, to power off your computer.
Download the extension here.
Extract the file and place the extracted folder in the ~/.local/share/gnome-shell/extensions/ folder of your home folder.
Restart Gnome Shell by pressing Alt + F2 and running r.