It's always good to take an orthogonal view of something. It develops ideas.
When in doubt, use brute force.
In fact, we started off with two or three different shells and the shell had life of its own.
A well installed microcode bug will be almost impossible to detect.
I think the major good idea in Unix was its clean and simple interface: open, close, read, and write.
That brings me to Dennis Ritchie. Our collaboration has been a thing of beauty.