If you would like you Kali OS to boot and go directly to command line login, follow this simple procedure below:
Thanks to the original poster of this great article, with lots of options and explanations, please make sure to visit his original post :
https://forums.kali.org/archive/index.php/t-453.html
TL:DR – Copy/paste this into a terminal:
cp -n /etc/X11/default-display-manager{,.bkup}
echo > /etc/X11/default-display-manager
cp -n /etc/gdm3/daemon.conf{,.bkup}
sed -i 's/^.*AutomaticLoginEnable = .*/AutomaticLoginEnable = True/' /etc/gdm3/daemon.conf
sed -i 's/^.*AutomaticLogin = .*/AutomaticLogin = root/' /etc/gdm3/daemon.conf
ln -s /usr/sbin/gdm3 /usr/bin/startx # Old school ;)