MINIX was originally a private project of ast. It worked very well for the goal of teaching student the basics of operating systems.
One thing that might have been a waste of time is making the MINIX utilities POSIX compliant. Then again, many students would like an opportunity to work on something like that. The ones that wanted to work on Linux could just do that. Students worked in their free time on lots of interesting projects that were unrelated to the university.