I got tired of this being the only application in 3 versions of macOS I've seen that can completely lock up a Mac to the point you have to hard power cycle it.
Here is how you quit the game without risking harm to your operating system by having to frequently hard power cycle your rig.
Using the editor of your choice, create a file in your home directory with whatever name you prefer and add the contents below. I name mine KILLESO.sh
#!/bin/bash
for pid in `ps -eo pid,args | grep 'Zenimax Online' | grep -v grep | awk '{ print $1 }'`
do
echo "killing pid $pid... BYE FELICIA"
kill -9 $pid
done
exit 0
Make file executable:
chmod 0700 KILLESO.sh
When you wanna exit the game, alt-tab ( or option-m) and run:
$HOME/KILLESO.sh