I believe in the present day, the premise motivating these undergrad books and courses based on alternatives (VU and Minix, MIT and xv6, Purdue and Xinu, God knows what else) is that Linux has become too complicated for an introductory course. I honestly don’t have any instinct as to whether this is correct pedagogically. I suspect the two main factors are how well the software facilitates getting students situated and in a position to do meaningful programming assignments quickly, and how motivated the students are to work on the software.

I reminder taking a security-oriented class ages ago and hacking on an operating system that was already dead as a trilobite, and we were all smart enough to realize this was not a triumph we’d be bragging about to our future children (or recruiters). Bleh.