Unfortunately your joke has wooshed over quite a few heads but what you say is true. The shell should be one of the most reliable parts of your operating system. Why on earth would you NOT trust the primary interface of your OS? Makes no sense.
I'm not sure I follow you but it wasn't a joke. Shell scripts are notoriously error-prone. I absolutely do not trust shell script authors to get everything right.
Also the shell isn't even "the primary interface of your OS". For Linux that's the Linux ABI, or arguably libc.
Unless you meant "human interface", in which case also no - KDE is the primary interface of my OS.
The shell itself may be reliable but shell scripts are notorious for security issues.