When I first looked at MUD code, I had not yet learned to code. I thought that the folks who wrote the code must be so smart, and felt intimidated by it. Fast forward a few decades, and I recently looked at MUD code again. I spent a week porting ROT 1.4 to a node server, mostly just as a personal coding exercise, and found myself realizing just how bad that code actually was.
Yet we need to be fair. As you said, it was written by newbies, mostly students. It was written before modern tech stacks, before modern practices. And despite all the critique we could throw at it... it worked. It stills works. It was shared, copied, modified, and kept on working for many people, over many years. And it definitely inspired people to learn and try new things.