the nice thing about standards is that you don't have to make sure the script runs in a billion different shells. You just have to make sure your code is POSIX compatible, and all of a sudden, all POSIX compatible shells will interpret it just fine! Isn't that fantastic?
There are also a relatively large number of tcsh users in the world. This is why, even now on latest fedora, /etc/profile.d contains csh scripts.
As for sh, standards exist for a reason. Try to empathize with people who are not in your bubble.