The main advantage is that if you screw it up or an update borks the shell itself, it's easier to fix if it isn't your login shell. At one point I decided to s

The main advantage is that if you screw it up or an update borks the shell itself, it's easier to fix if it isn't your login shell. At one point I decided to set Elvish as my login shell, and it turned out to not function as a login shell. As in, won't start at all. Any time I logged in, it would just immediately exit, ending my session. Work doesn't allow us to have root access (annoying), so I ended up having to boot into single user mode to set my shell back. I've done a similar thing with bash and "set -e". Being new increases the chances of doing something like that that breaks the shell. It's annoying to fix for those of us with experience, and extremely difficult to fix for those without experience. It gets even worse when you consider that some distros like Ubuntu don't set a root password, so you can't log into the root account without sudo, which requires your user to have a functional login shell. I wouldn't want a new user to paint themselves into a corner where the only way to get their desktop working again is to remember how to boot into single user mode or boot from removable media and mount their hard drive. Doubly so if their Linux desktop is their only PC; it's going to be really annoying if the only way to write removable media to boot from is the machine that's currently broken.